Denon is a fine starting point, I have the 3311ci with airplay and like the feature alot. You might can find a 12 model like 2112 discounted pretty heavily since it is last years model. It will have audyssey multieq XT and airplay. Amazon shows 488. Electronics expo shows the 2312 for 600, with free shipping and usually calling customer service will get you an additional 20-30 percent off. They had last years 1612, albiet no airplay for 200 bucks prior to any customer service rep discount. But shop around. I'd try a couple of denon factory authorized refurb sellers. You might find something real good there. assessoriesforless. Check denon's website for factory authorized refurb sellers
Your budget needs to be around the 800 mark and probably bookshelves. I'd forgo the sub for now and get the best bookshelves you can and spend as little as posssible on reciever. Add the sub later when more funds allow. Trying all three for 800 bucks will result in some serious audio quality compromises.