Hi frosstyx. Good instincts. Not sure how far your knowledge goes, this is kind of beginner stuff but may benefit newbies who find this on a web search. What you describe would match 2 kinds of Cree LED's, both of which are commonly available, and cheaper than XM-L:
- Cree XR-E R2 (usually referred-to simply as "R2"--use this term when searching). The R2 is the most efficient version of the older XR-E LED die. It is a small but bright emitter, which makes for good throw. They usually only ever pull in the lower 1.x amps or so tops (3-4 watts), whereas an XM-L is like 3-4 amps, around 10+ watts. Basically, you'll get the same/similar brightness of hotspot as an XM-L, but just a smaller hotspot. So, again, my statement about shining in peoples' eyes would stand esp on high. BTW, if you ever see "Q5 and "Q3" etc, those are lower brightness ratings of the same XR-E format. I own a cheap host with a 1-mode R2 drop-in. It doesn't get much use; I use it mostly for working on cars when I need a bright spot and generally good runtime. If I had to have a 1-mode which could do longer runtimes, it's a good choice. You get your throw and ok spill for only 3-4 watts, pretty good deal. Having multi modes not really so important with these lower draws (which used to be considered high, actually), I'd just practice good pointing procedures/etiquette. With peoples' eyes it's about lux (how much focused light on a particular area, like a pupil) more than lumens (total light output). 1-mode R2 would be true KISS.
- Cree XP-G (of any brightness bin--they're all good in my opinion). This one was developed in-between the XR-E and XM-L. All of these are nice LED's, just different. XP-G has a bigger surface area which is not as bright per amount of surface area, but nevertheless puts out more light because it's bigger. As a result, the light is better for floody applications, kind of like XM-L, but is good all-around, like XM-L, just not as powerful nor as power-draining. It's basically a smaller version of an XM-L. Ones driven pretty hot go up to about 2.5 amps (8+ watts or so). The R2 with a tight focus is still going to have a hotter hotspot, even though it puts out overall less light. I have all these, and conclude: the XP-G is best for "walks" (walking around). Puts a nice, more even light. Probably good for 'cop stuff' in terms of writing or general walking around. Will be bright, but not as harsh if you nail people in the eyes as an R2 driven at the same level ,due to more distributed light. Will not 'throw' as far, but it depends how far you need. R2 still rules 'spear' type 'dedicated throwers' but... those things are unitaskers. You could get one later (you WILL buy another light if you get into this) and keep it in the car if you need to shine on a perp hiding in a wheat field.
Few things in this hobby are more personal than reverse vs forward clicky. You get far more options in reverse though. The main reason mfr's like to use them, is, it's easier to change modes with reverse clickies. Reverse offers momentary off. Forward provides momentary on. In other words, it'd be a lot easier to send 'morse code' signals with a forward clicky. Multi-mode drop-ins change mode by sensing that the power was turned off briefly, then back on. So a 'momentary off' press equals a mode change. I prefer to have momentary on (forward), because I don't usually use lights for long periods of time, and often need them for just short burts. But, I think more prone to accidental turn-on (in pocket or bag). When holstered, less of a concern. The standard L2P comes with a switch which is fully shrouded and has a firm resistance. By nature, not as easy to activate, but very unlikely to go on accidentally. For a beginner who wants a forward clicky I'd recommend buying a ready-made solution (whole tailcap or flashlight) rather than trying to mod your own tailcap, unless you're handy and like that stuff. Shiningbeam.com sells Romisen brand forward clicky tailcaps which are reputed to work with Surefire/Solarforce threading. Whether they're "professional" quality, is opinion and I don't own one so have no comment. As you read, Solarforce does have forward clicky lights.
If you're planning on getting a number of batteries, I don't know if you saw the guy on here who's selling 10 sanyo 18650's for around $20 delivered, but they're unprotected. I number all my similar batteries with a sharpie marker, and now and on some put a dot every time I charge. Larger unprotected li-ion batteries make me a little nervous, though I own a mix.
My humble opinion, not a recommendation here: If I were a LEO doing night patrol, and were pulling people over, I wouldn't want to mess with 5-mode. If I needed some special infrequently-used feature, like super throw or a special strobe, I'd keep a separate light for that. I'd try to practice KISS. If I had a multi-mode, I'd do a 3-mode high-med-low or 2-mode non-strobe, and they are hard to find in cheaper, budget-oriented drop-ins. Most notable exception is the Manafont-sold genuine Ultrafire 3-mode XM-L which changes modes extremely well and appears to have a 0-drain memory? Really depends how budget you want to go. Don't have any Nailbender items, but I'd seriously think about it in your shoes. You need to decide how many modes you want, the kind of throw you really need in a holstered light, and how much of a jerk you want to be with the shining in peoples' eyes. Do some experiments on yourself when your eyes are night-adjusted. XM-L is a nice less-spotty light and on low modes wouldn't be any worse than anything else--I'd just be worried about 'forgetting'. With 2-mode, it's more difficult to make a mistake. I like the flexibility 3-mode provides. High for bursts when I need it, Medium for most stuff, and low for close-up things.
Another option... I personally have come to like the twisty/momentary (non-clicky) tailcap system used in older Surefires, but most don't. Surefire (belatedly) responded to the explosion of 3rd-party clicky accessories for the 6p, so now it looks like it's mostly if not all clickies from Surefire (from my memory of their site). If you manage to get an older genuine Surefire 6P twisty tailcap, mine at least works perfectly on the Solarforce L2P, and mixed results with other models, and the plastic Surefire G2 tailcap doesn't work on any host I have, fyi. You might be able to sucker a colleague with an older twisty Surefire 6P into a tailcap trade for a cheap clicky ;) . Or at least try his on yours and see how you like it (maybe trade for awhile--they'll probably interchange).
This is an important decision for you, but you're not limited to 1 decision. The thing is, though, the fact you're posting here almost guarantees you'll be buying a number of flashlights (and accessories) in the next year! It's worth having the discussion, and although fundamentals are repeated and it gets old for some of the seniors, I've never actually seen a thread of a LEO flashlight newbie asking advice on a budget duty light. :) I'd try a couple competing solutions, see what I liked, and mix and match! That's the main advantage of the so-called "P60 host" system (Surefire 6p-derived designs). No better market for used flashlight gear than colleague leo's anyway, probably. Pretty soon you'll be training THEM i think.