You should post your questions about receivers inside one of the other posts you made on receivers. That way the forum doesn't get filled with zillions of individual posts that ask related questions. It just keeps things simpler in the forum. Thanks.
I doubt any receiver that could send 400 watts to a single speaker is in your price range, so I wouldn't worry about it. I'd shoot for a receiver that does 100+ watts per channel at the very least, but more power is better.