Lights are not necessary unless you're breeding. For a baby, a basic 14 on 10 off or 12 on 12 off is just fine, IF you even use lights. You asked about size, well, for my babies (up to around 500g or a little larger) I use 15qt sterilite tubs. The ambient temps in the room I'm keeping them in is around 75, but with the flexwatt going across the back of the tub (3" strips), it creates a hot pocket in the back of the tub, and while the floor temps are 92 to 94 in the back of the tub, the cool side still gets up to around 82 to 85 with ambients IN the tub getting up to around 82-84.

In order to get rid of some of that extra humidity that the plastic will help you achieve, drill some holes along the FRONT and side of the tub to help circulate the air and let out some humidity.

I use both a glass tank for my male, and a rack system with all plastic in it for my girls (and future males), and I can tell you from experience and much headache, it's MUCH more constant and a lot easier to control temps/humidity in plastic than it is in glass!

Good luck, and welcome to the forums! It's a great place and lots of people have really good info!