The astroturf looks nice, but you are going to have one heck of a battle keeping it clean, and it will smell. Maybe stick on floor tiles might be a better choice? Can be cut to fit with only scissors. Then newspaper over that that you can just throw away as needed.
See what works for you, but anything permanent like the indoor outdoor carpeting may become a headache to deal with. The iguana doesn't care how it looks!
You really need a thermometer or two in there to have a constant read on the temperatures. They sell cheap (less than 10 bucks) ones at all the big box stores.
What are you doing for night time heat?
Might want to put a clean rock or something in the water dish to keep it from being spilled.
Have you seen the food chart here on this site?
Lots of other good info in the links at the top of the home page here as well.
Good luck with your new green baby!