I don't know about you, but with expensive electronics I like to buy from an authorized dealer so I get a warranty. I don't know how Pioneer is about theirs. I happened to get my 1015TX from Best Buy through a friend, so I got a super deal. There are some really good e-tailers though. That's my only caveat. I think for your purposes, the Acoustechs would be a better bet. Their high efficiency means you can really fill your room with sound with that receiver. The only issue now is a subwoofer. With that size of a room, you're going to need a beefy subwoofer, or two
As far as setup goes, the MCACC is pretty accurate, though to get the best sound you'll need to manually tweak. All you need to do this is an SPL meter from Radio Shack, a tripod, and some patience. Set up the tripod with the SPL meter attached in your primary listening position and play test tones. For the calibration volume, you should try for 85dB (Dolby standard). This means that at the listening position, your SPL meter should be reading 85dB for every speaker. Once you level match your system, it will "gel" much better.
For test tones, you can use the receiver, though setup DVDs like Avia and DVE (digital video essentials) will help you with your sound and video tweaking.
Lastly, don't forget to address acoustical issues. Your room and speakers have by FAR the biggest impact on your sound. A lot of people try to fix sound problems and end up bypassing the thing they started with before they bought any gear...the room! What kind of acoustics does your room have? Reflective? Dead? IE, if you clap, does it echo a lot, or just make more of a dull "thud"? What kind of floors do you have? What other things are in the room? Drywall, bookcases, etc?
One thing to note: your room will have some bass modes. That is, at certain bass frequencies, you will get tons of bass, and at others too little. This can be addressed somewhat with the placement of the subwoofer, but can be really controlled with a good parametric equalizer. Some subwoofers include an equalizer for this purpose. If you end up going for a sub(s) that does have a parametric EQ, then you might think about getting something like a Behringer Feedback Destroyer or DCX2496. These will allow you to precicely EQ your sound and make it flat (which equates to good).
Whew! That was a long post. Feel free to post some more questions (and answers to my queries, because you're bound to get them from someone sooner or later!).