Funny thing is that those speakers are about as small as they can be to get down to 80 hz, which is the recommended frequency at which to redirect bass from the main channels to the subwoofer. With smaller ones you'll have to go for a 100 or (more likely) 120 hz crossover instead, which may make the sub a localised source of sound depending on its placement in the room and the surrounding acoustics. It is possible to minimise this problem with appropriate setup, however. (For reference, 80 hz is approximately the pitch of the E below the bass clef, while 120 is closer to the B above that, rather higher into male vocal range.)

Amusingly, audiophiles often lament the inescapable influence of WAF (wife acceptance factor) in making their purchases. I'm grateful not to have been restricted this way--though I did make sure to get nice-looking speakers. ;)

Anyway, receivers--I haven't really been keeping up with the latest developments or specific models, but I can recommend Onkyo receivers without hesitation, as I own one myself. They deliver good sound quality and are well put together, even in the lower models, and are also quite user-friendly. Don't underestimate the importance of this--while Denon makes good quality products also, their interface and user manuals are nearly unintelligible, and I avoided them for that reason. You should be able to get a good entry level Onkyo for $200 if that's the way you want to go, and I think you'll be happy with the Energy system.