as far as your bp is concerned the darker the better. the T3 that i have came with a detachable flourescent light fixture inside. i'm not sure if that is standard but you could always call and find out.

it is really easy to assemble. i got mine used and so it had no instructions but it was still really easy.

i no longer use mine because i switched all my bps over to rack systems. i got the belly heat option on mine--a heat cable routed into the bottom of the cage. my one complaint is that with cable you get hot spots as opposed to more even heat that you get with flexwatt tape. a lot of people use this same model as i have though and have no problems with it. i may just be a little overly obsessive about it.