I use abbey predator gas in mine, runs fine and it's got lube in it to stop your seals perishing etc.
As for cleaning/lube I just recently disassembled my stock TM glock 17 after about 18 months of zero maintenance, four drops of oil and it was back to peak performance!
Holsters are a bit of a pain, since the TM Glock is slightly wider than a real one, Fobus ones fit without mods though and they do a range which will accept flashlights too.
Speaking of flashlights, I'll second what proffrink said on the element X300 clones, they're decent for the money. Though if you really want to blind the fuck out of people in CQB go for a genuine surefire X300U, leave people seeing little purple blotches for about 20 minutes