help choosing receiver...tx-sr503 or sr702

[venkman]

Hi, I just moved into a new apartment and desperately need a new receiver. My old Kenwood 107-vr is just too old and the back channels come and go. Anway, my living room and kitchen are in the same room and the living room portion is 14' 7" by 17' 7". I am in a apartment so I can't really blast my system, but, I want a quality sound. I was never happy with my Kenwood but being in college wasn't a great time to get a nice receiver. I currently have a JBL PB12 subwoofer, Klipsch KG 3.5 fronts, a Bose vcs-10 center, Bose 301 rears (have rain damage). I am planning on buying a Klipsch center and rear channels cause I wasn't too happy with my current center. Now the real question. I am debating between the Onkyo TX-SR503 @ 269.99 (circuit city) and TX-SR702 @ $548.81+ 50 shipping (amazon). I am planning on building a new case for my computer and placing it in my entertainment center and using a plasma, lcd, or dlp as my monitor after christmas. I plan on using my reciever for watching tv, dvd's, my computer sound, LP's, and listening to my mp3's (all very high quality mp3's). None of my friends know anything about home audio so any help is GREATLY appreciated. I am open to any and all suggestions and am in no way dead set on these two receivers. My parents have had an ONKYO stereo receiver for years and it has always just been a great sound. Thanks!

[venkman]

also now looking at TX-NR801. Any real differences between the TX-NR801 and the TX-SR702?