<font color='#000000'>With that info, I'd look at the Denon 1804, which should easily meet your price point -- also the recent Harmon/Kardon's, either the AVRX30s or AVRX25s, which are very well liked. I own a Yamaha RV-1105, which I like, but I wouldn't recommend a Yamaha HTR line (or, today, my RV-1105, since discontinued) because of 1) the alleged power clipping issues on 4-ohms (should you decide to upgrade), 2) bass management. Not sure what it's like on the HTR series, but you will want really good bass management on your receiver, given the absence of low-end on your Athena mains. (That's kind of a silly point - even with great-bass floorstanders you'd want really good bass management.) If you wanted to purchase a Yamaha, I don't think they make sense right now until you step up to the RVX-1400 (and 2400), which have improved bass management plus some other great features making them stand-out and long-term performers. Problem is the lower-priced 1400 starts about $600 or more.
You might find this thread on the Axiom forum interesting, someone seeking advice on a similarly priced set of AV receivers:
Axiom Thread: AV Receivers < $400. (If for any reason that link doesn't work, just go to the forums on Axiom.com and do a search for 1804 and it'll come up.)
The link below at Etronics list some base online e-tail prices for the Harmon/Kardons and you can see the Denons there as well. Any of these receivers should meet your needs nicely -- the Denon 1604, 1804, 2803, H/K AVR 230, 330, 325, or 525. If it were me I'd spend a bit extra and get the H/K AVR 525 because it has received lots of praise from users on the Axiom forums. (Or save money at get the H/K 325.) I know the Denon 1604 indicates the bass management only goes down to 80 Hz. While this will be fine with your current speakers, it could be limiting in the future. You'd probably be better served by a receiver with more flexible bass management settings, which the H/K 525 and Denon 2803 have. Also, both of these receiver lines are said to have actual watts per channel outputs that match well with the levels advertised -- a bit of a controversy in the AV receiver world these days. (The Yamaha 1400 and 2400 score well here too.)
Bottom line: Spend more well now, regret less later.
Harmon/Kardon receivers listed on etronic.com.
Birdman</font>