Perhaps the Densen DM-10 inteegrated amp. It would fit in the second (under $2K) group used, I believe. It has all you mentioned your current setup lacks. It has grunt, deep bass, Biiig Sound/stage, awesome resolution and detail not to forget a very musical (almost tubelike) quality. I like Spendors very much and would own them if I had a smaller room...
Cheers!