The biggest difference between the 3 series and the 22 series is that the 22s are more detailed and share the same drivers, thus timbre, as the Axiom center channels. The 3 series has a more laid back, lower toned sound. They both would work very well in your size of room. The EP500 would not be too much for your space as you calibrate it to match the rest of the system, it just gives you more headroom for really demanding scenes, if you can afford one then by all means get one. The other option would be to get an EP350 which might allow you to get the W22s instead of the W3's. There really isn't alot of difference between the 350 and 500. The 500 can play a little lower and has even more headroom, the only way i think most would notice is during an A/B listening session, especially in a smaller room like yours.
You can save a few bucks by going through the Factory outlet as well. These are speakers with cosmetic deficiencies that many of us have yet to find on our own FO purchases. You save 10% and will get an additional 5% for a HT discount(5 or more items).
