Please, i would like input?

ok, so im getting a baby Iguana(8"-12") and was trying to decide. Free roam or cage? i have a 36" long, 17" high and 17" wide screen cage that is all setup and everything. but, i was thinking of letting it free roam in my bedroom. i am 16 so there is no young babies in here and it stays fairly warm(75 F) since it is going into summer here in NJ and we dont us AC often. i was thinking of building a ramp so he can get in and out of the 46 gallon reptarium. so he can bath in there and eat and poop and then walk around my bedroom where i will put heat/uvb lights. so do you think its a better idea to start him in the reptarium then move him out into my bedroom or just combine them from day 1. and i am not a beginner reptile keeper, ive had ball python, water dragon, now i have a schneider skink, a snapping turtle and a Japanese newt. and also i was thinking of using a water tub so he would go to the bathroom in there, any tips on potty training are appreciated.