Which preamp for Symphonic Line Kraft amps?

Hi All;

I'm in the process of receiving a pair of Symphonic Line Kraft amps to power a pair of Dali Megalines (using a tube crossover). I'm currently using a Dodd battery powered preamp and am thinking about upgrading to either a Symphonic Line solid state amp (RG3 mk4) or the new CAT Renaissance (replaces the SL1 Ultimate mk 2?).

I'm guessing the best way to find out would be to use my ears if I can audition both units in my system, but these aren't items I can drive down the street to pick up...

Any thoughts would be appreciated though, especially regarding the SL preamps...