Here's another "welcome."
John has covered the bases very well, but I'd like to add a "what he said." Most of us here understand the concept of "limited funds" very well. In a room the size of yours, if you are truly interested in HT, you will eventually want to build a surround system with a subwoofer. But, when you are on a budget you just do the best you can, with what you can afford. And, John's suggesting the Onkyo 504 and a pair of M3s, as a way to start, is spot on.
If you'll check the
Auditioning Axioms in Your Area thread in the "Hearing Things" section of the forum, you may find someone near you who is willing to audition his speakers for you. An audition would give you a good idea of the Axiom sound, and demonstrate what a surround system can do.
