I wouldn't worry too much about the amp/speaker interface. The single most important arbiter of sound quality is the speaker/room interaction. After that, source material plays the biggest part.
There are many, many speakers that would work well with the Krell amps. There are not very many that will work well in your room. If I were you, I would find the best speakers for my room and then start to investigate amps to pair with the speakers...
-RW-