My only experience with HID is with dive lights and the one I had was only 10W but the bulb itself (replacement part) was close to $100. If you go with HID make sure you know how much the replacement bulb will be.
They are also more delicate. If you drop it while it's on (hot) the bulb is probably toast.
At least with mine you also can't just turn it on and off without waiting like you can with LED. Balast needs replacing as well.
The Auto type HIDs can hot-restrike, no issue at all. I must have strobed them hundreds of times like disco doing signalling. Heh.... It just runs them down a bit from 5,000 hours, no biggie. Like your flurorescent tubes (not supposed to strobe them bro). One thing that is extremely hard is overdriving and esp if you like to point the HID more than 45 deg up, ie burn position. If guys can gun P60 XM-Ls at 3.5A with lousy heatsinking, you can do the same for HIDs. Each 55W bulb is just like 6.50 bucks shipped. I think I must have close to 30 bulbs in total here, waiting to be abused. 
I purchased the generic flashlight form bulb + ballast combo before, believe it was $40 shipped EMS, unit price is $24 or something. So not that bad. Battery is around the same.
But of course I'd not encourage you you to go HID if you don't need the pros and are affected by the cons, as you can clearly see it is not for the usual folks. Start with the small stuff like SST-90 first and slowly build up when you have the urge for more light. :) I mean come on, you are not aiming to be able to hit 1 million CP mark with just 150 bucks and expect zero cons? But talking about your needs with 35% flood requirement, i think the Ebay/Ali flashlight HID is good.
12V 7AH SLA is just usd15 a piece here, or a pair of XTAR 2600s on offer. :)
I guess I don't understand the difference between the different applications with HID. A 10W Welysh Allen light bulb is close to $100. I know the HID bulbs for work bench lights are $10 or less so there's something I'm missing obviously regarding HID :)
Im just not feeling the HID and its purposes will fit much into my needs, And i have very few needs and could have bought a KD C8 and i would have bought all the lights id ever need in reality. But this is a hobby and not a necessity thing for me. But i do need to justify very pricey purchases so im not spending money on stuff im just looking at everyday and get no use from it.
Id prefer to build something, But thats not so easy with HID imo. But i do think an SST-90 build with well matched emitter and driver run off of 2x 26650 IMR cells would make a really strong light. So im still looking at the host 2x 26650 from CNG or the SST-50 version since its only $20 more and i can reuse the old parts in another light for alot less than i could buy them for.
If you're looking to reuse parts, you might even look for a 18650 x 2 host and get IMR's. Like the fandyfire stl-v6/ skyray stl-v2 ~50$ and pop a ssr in there. As long as the 9A driver fits the reflector should work ok as long as you focus it right.
A Philips D2S is also close to 100 bucks. They do perform some higher wattage ones do 120 lumens / watt. The Chinese ones usually are not that bright/efficient, some have arc chamber deformities after certain hours as the QC is not very consistent etc. But they do not really matter to us hobbyists who are just after having fun and the occasional blast for a few hours every week at most. Like there are applications/needs for AW IMR cells and also apps/needs for BIO IMR cells (quite good, there are some good info here)
Like some of the Ushio sealed PAR64 cans and the Chinese cans and bulbs, it is $600-1000 for Ushio/Philips bulbs and $50 for the Chinese ones as I have shown above. This is why they can churn out a 100 million CP advertisement searchlight for usd400, and shipping to Taiwan is just $200 via EMS and $350 here.
Of course if you have a specific use for it, then go for the good stuff. HIDs also generally have better CRI than LEDs.