You could get the 5 mode version and some protected sanyo 16650 from international outdoors, coupled with a good charger and your all set. 
I got a reply from KD today about their 1 mode drop ins.
They are listed as 1400 lumens, but this canāt be right with 1.8 A can it? I guess we will see :~
Thank you for the info. My EOTech exps3-4 uses a CR123 battery it would be nice to only carry one type. I appreciate your help and all the great info here. One more question. What is a very good charging solution for the protected 16650s. Thanks
No. They often list maximum lumens, or sometimes more. Its āchinese lumensā. Never trust them! 
XM-L2 should be around 1100-1200 emitter lumens @ with 3A to the led.
1,8A should give it around 770 emitter lumens roughly estimatedā¦
You can toss out the 1400 lumens right off the bat. That was never going to happen. I wouldnāt be surprised if 1.8A is correct. With a P60 drop in that is about all you can run before thermal sag drops the lumens down anyway. At 1.8 your could still be looking at around 800 lumens which is a ton for a tiny P60. This is a list of the different LEDās and what they run at. 1.8 might be all you really want to run with a normal P60 for anything other than a short time anyway.
http://flashlightwiki.com/Cree
I expected that I would be swapping out the driver anyway but if the 5 mode is direct drive I will probably leave it as is. I didnāt pick the 1 mode because I guessed given the stats that it was higher resistance. Mostly because, if it can handle higher voltage than it must have a buck driver.
This was the driver I was going to put in. I still might.
I ordered a 1 mode 3-18v drop in on 03/06 from Kaidomain status Back-Ordered 
2 PCS Sanyo 2100mAh Li-ion Battery (Sanyo UR16650ZT) Protected(Black) from Flashlight-International Outdoor
XTAR WP2 II USB Charger on ebayā¦
This will be used in a weapon light mounted on an M4. I hope this config works together. My Surefire currently holds 2 3v CR123s. Thanks for your help Ian2381
Does lightmalls ship out their drop-ins?
It seems like KD does not.
Before I ordered the two different drop-ins from Kaidomain I knew I did not like their store from earlier experience with customer support. But why not give them a 2nd chance. (And I really wanted to try these :p)
Their site says. āShip in 1-3 days business daysā
They have now had 5 business days to ship it.
Status: āback-orderedā
Have any ones order from KD shipped??
The U3 drop-in I got from Lightmalls was underdriven. Iād trust Kaidomain over them to drive either DD or else pulling 3ish amps, although Lightmalls has some welldriven stuff. Their U3 C8 is a blast of light.
Yes the site says my order from almost 6 days ago is back ordered as well. I got an email saying it had shipped out but the site says otherwise so iām not sure whatās upā¦
I emailed KD about my back-ordered drop in. I got this in response.
Hi friend,
please donāt worry about back-ordered, it means waiting for supply. we are arranging your order now and will ship your order as soon as it is available.
Have a nice day.
My updated status is Order Pending
LOL
My status have gone from āback-orderedā to:
āOrder pending-packingā
I have a feeling they will be āpackagingā until the order is not back-orderedā¦ :Sp
Me tooā¦ Thank God it only gets dark once a day!! LOL
My KD XM-L2 drop-in was backordered but finally shipped.
If I were to run 2 AW 16340 Lithium Manganese (IMR) cells as apposed to a single 16650 with the Cree XM-L2 U2 1400 Lumen 3V-18V 1-Mode SMO LED drop in would I see a difference in output? This is an upgrade for tactical use i am trying to get the most safe lumens/lux otf as possiable. As I mentioned before my light holds 2 CR123s. Thanks
Possibly. Output should at least remain regulated until protection trips on the AW cells, whereas the voltage of 1x18650 cell may not be sufficient for regulated output for the entire runtime (based on my observations with similar high-voltage dropins).
Mine is now shipped too.
I think its a bad way to make business though. Put out products that you claim to ship out fast and then you donāt.
Manafont got these drop-ins (which are most likely the same) in stock the same day KD started to ship out.
I would much rather buy them from Manafont. I have much better experience with them. (And they were 1$ cheaper too.)
I plan to send a mail to Manafont and see if they can check tint/bin.
I got an update on my orderā¦ LOL
Hi friend,
sorry for the delay shipment.
We will ship your order on this saturday.
have a nice day.
After the drop-ins got shipped from KD they arrived with the speed of light!
Arrived 19.03. 16 days after I placed the order.
I have e-mailed KD, they claim it is U2 despite the others site who have simular products either sell T6, or dont know the bin.
Tail-cap readings:
3-18V driver is 2.1A on high, but start sinking right away if you use it with a single cell.
About 1,9A at 4V
About 1,6A at 3,75V
KD claims 3-18V. They are wrong. It is 3,6-18V.
EVERY time I order something from KD they remind me that they always mess up descriptions, shipping, customer service or something. I should just stay away from that storeā¦
The 5-mode driver is 2.6A on high on freshly charged batteries. But that goes down towards 2A when battaries are drained just a little.
When batteries are at 3,76V output is 1.7A
Basically, the driver is quite bad.
Im still happy with the buy thoughā¦
I did a driver swap, so im now pulling up towards 3,9A on a fresh battery! I am using the āoldā classic 3-mode manafont driver.
But, it sinks down towards 3,5A quick and then continues downwards.
Nice! Those are encouraging results.
How long before the amperage of the 3-18V driver drops out of regulation on 1 cell?
I noticed today that FastTech has added an Ultrafire P60 XM-L2 drop-in, although it's 5 mode. Only $10.89. Specs say 2A output.
-Garry