How to do a skylight?

My daughter has asked if I can put a skylight in the top of her camper.
She wants more than the vent.
I'm beginning a build of a simple/rimple type on a 4x8 HF chassis.
So, is a special window needed? Can I just use a non-opening RV window like this:
http://www.ebay.com/itm/NEW-BLACK-KINRO-18-X-30-RV-FIXED-WINDOW-CAMPER-ENCLOSED-CARGO-TRAILER-18X30-/351253908006?hash=item51c85d4a26&vxp=mtr
Thanks for any helpful suggestions and experiences in advance
She wants more than the vent.
I'm beginning a build of a simple/rimple type on a 4x8 HF chassis.
So, is a special window needed? Can I just use a non-opening RV window like this:
http://www.ebay.com/itm/NEW-BLACK-KINRO-18-X-30-RV-FIXED-WINDOW-CAMPER-ENCLOSED-CARGO-TRAILER-18X30-/351253908006?hash=item51c85d4a26&vxp=mtr
Thanks for any helpful suggestions and experiences in advance