I have no idea what your room size is but if you're in a house rather than an apartment then I think my first priority would be a big bad subwoofer from an internet direct manufacturer like Hsu Research, Outlaw Audio, or Rythmik Subwoofers first. That's something that's going to really get your attention. You size the sub based on total room volume and each of the above will help you with that.
In phase II I'd start looking at speakers because they are going to give you the next most noticeable improvement. Once you select the speakers you can start looking for a receiver that meets the needs of the speakers you've fallen in love with. I'm not a fan of non-Elite pioneers because of their historically "optimistic" specs but Accessories For Less usually has good deals on factory refurbished Denon (like the
2112,
2312, and
3312) and Marantz receivers. I'd also watch for sales on Denon receivers because there have been a lot lately due to model year changes - the "13s" are out.