Lots of good advice here but here is where to start. Bring along your favorite music (a variety to listen to) and pick out a pair of speakers that you like first. Once you hear the pair you like then you can find out from other Agon members with the same speakers what amp to mate the speakers with. You DO NOT have to spend big bucks to get great sound, just system synergy. The Krell amp is very good for the used prices they go for but not for the $4K list price. Once you have the speakers and amp matched up, then focus on a source and then a preamp. There are some who will tell you that the preamp is critical for great sound and they are right but you need to hear what a good source will do first and then see what peramp will provide the best sonics and not reduce the sonics of the source.
Hope this helps.
Hope this helps.