I disagree with the tube pre recommendation. I tried a Sonic Frontiers Line 1 into a Classe 15 for about a year. This replaced my Classe 5 pre for a while. Although this combo sounded nice, it didn't sound as good as my Classe 5 driving a 40watt tube amp into the same speakers. Not to mislead you though, the Classe 15 does offer more slam, but the midrange of the tube was to die for.
Good luck, I too am moving on to a tube based system.
Good luck, I too am moving on to a tube based system.