Hey there...i just got my beardie...i've had my 4 leo's for a couple months now and have done a lot of research on them...anyway...i agree with everyone else...start off with one...or if you want to eventually breed them...you can house 2 females with 1 male and everything should stay copasetic...from what i've read males get territorial so more than 1 male should be housed seperately...i'd go with a 20 long if i were you...i have 4 in a 20 long and they cohabitate nicely...if you do plan to get males and females...males become sexually mature at about 10 months...whereas females at 12...so if you get a male make sure to pull him out for the extra 2 months of maturity required for females (either way you won't know the sex until after about 6 months)...anyway sorry i'm rambling...
yo get started a 20 gal long with 1 leo or maybe 2 until you get aquanted with keeping them...all they need is a nocturnal light (a red one) and don't need a UV-B or basking lamp...they like to hide...so make sure to include at least 1 hide per gecko (a deli dish with a hole in it does well)...my cage stays around 80-84 degrees on the hot side and around 75-78 on the cool side
sorry rambling again lol...anyway good luck with your leo's...just check the care-sheets on the site and read thru some postings...this site did me very well when it came to learning about these guys...again good luck ;D
-S1N