I would look at both the AVR435 and the AVR635. They are very similar in sound and operation, with the AVR635 being slightly more powerful and having OSD available via component video.
Both feature HKs new parametric EQ system, EZset EQ which will actually EQ your sub. Eq systems from Yamaha, Marantz, Pioneer and Denon (with the exception of the flagship 5805) cannot EQ a sub as they do not adjust frequencies below 80 MHz.
Chris - what models of the Acoustic Energy speakers are you running? The flagship Harman receiver (7200 / 7300) is a terrific sounding piece but it lacks the EZset EQ that I find makes a big difference in my listening room. As for power, I find the AVR635's 75 watts per channel of power more than enough to drive my speakers and fill my room (5500 cu.ft.) with ear splitting sound - so much so that I sold my additional amps (Bryston, Anthem etc.). I typically watch tv at -40 to -35 and movies at -30 to -20. Considering 0 is reference, I don't think the 635 in my room is hurting for power or headroom.
Also i went up to circut city abd they had a 635 on display. i dont know if it is gutless or what, but i had to turn it up to -20 to get any sound, i was rather disaponted. The yamaha at best buy was at the same level and blew my ears out? could it be that the H/K was hooked up wrong?