I would check out NAD if you are looking for new and rega or creek if you are looking for used.

You should be able to find a used creek 4330 for about 300 or a Rega Brio, both of these amps sound great and will give you a good taste of the "hifi sound".

Anyway, good luck with your search, if you have more questions shoot away:)

Those are very amplifier friendly speakers and should work well with almost anything from the standpoint of being easy to drive.

I'm assuming you are considering the Denon for its home theater use and really couldn't offer any suggestions except to say that Denon is highly regarded in Europe for their HT stuff. I kinda doubt that you can expect great hi-fi performance from a receiver at that price point and designed for HT use, but that doesn't really mean much if you don't have a good reference point for comparison.

I would only suggest that you visit a local hi-fi retailer that specializes in audio and avoid the big-box retailers until you have heard a good sounding amp so that you can have a reference point to compare sound reproduction.