Lighthound.com has L2 "empty" hosts (no lamp or LED module is included): $12.99.
This should be your starting point as it's a known reasonable quality host at a great price. The host will support tons of D26 drop-ins and different battery configurations through extensions and such.
You should consider a 3xCR123 length setup to achieve the output you are after if you are really wanting to run CR123s (that will require a 1xCR123 extention). Look at your rechargeable options if at all possible. Operating a 200+ lumen incan on CR123s will get expensive fast unless you don't plan to use it much. A 2xIMR16340 setup without the extension can actually do anything the 3xCR123 configuration can do safely and more, just with less runtime, but it's rechargeable. ~200-300 torch lumens is attainable in that 2xIMR16340 config, but runtime will be down in the 10 minute range. The EO-9 will deliver over 200 torch lumens fresh off the charger, or with fresh cells, through the discharge you can expect to drop below the 200 mark at some time.
Personally, I would shoot for a 2x18500 (AW protected) (same as the 3xCR123 length configuration) size light. Also, personally, I'd slap a D36 conversion head on there from LumensFactory and run something like the SR-9L, maybe the HO-9L or something like that. Those lamps on a pair of 18500s are just really great outdoors and move lumens down-wind so much better than D26 lamps. (peak beam lux of a D36 lamp assembly is on average more than double an equivalent power D26 lamp). The increased beam intensity in my experience off-sets the need for more raw lumens in outdoor settings. The SR-9L will run for a good 45+ minutes on either 2x18500 or 3xCR123s in the same host and is more competent in outdoor applications than any D26 you can run, even though it would only qualify as maybe a 160 "surefire lumen" light.
Everything I have mentioned above can be ordered through lighthound. If you decide to do a 18mm diameter li-ion setup, you will need to make sure that the 1xCR123 extensions that they sell are cut to 19mm inside diameter, some out there are and some aren't. Also, you would need to pick up a charger if you go with a li-ion rechargeable setup, and personally, I don't much care for the li-ion chargers they have available there at this time. I would suggest doing some more poking around on CPF if you are leaning in that rechargeable direction and see where you can turn to get something decent.
Let me know if I have totally just added a heap of confusion here.
Eric
