I have heard both extensively. The Wilsons are very revealing speakers but a little on the dry side by themselves, in combination with the Krell they get pretty analytical and fatiguing after a while. However being this a matter of preferences, I acknowledge that many people like this combination. I have a good friend that has it with also a Krell cdp/pre unit, extremely revealing but a little bright arid and fatiging. You have a much better front end (one of the best) so should'nt be as much.
Levinson gear on the other hand, would give you a more musical and less analytical/fatiguing presentation. However if you want to really get your system to play music, do your self a favor and try the Lamm M1.1 hybrid monoblocks. They are mainly solid state amps. with superb punch and a single tube in the gain stage that will give you an superbly musical presentation with all the virtues that any Krell or Levinson gear may offer and much more,check it out.
If for any unthinkable reason you are not convinced with Lamm, other worthy alternatives and better matches with your speakers would be Jeff Rowland (specially the old gear, 8Ti and 9Ti) or Ayre. But please, whatever you do, stay away from Transparent cables which tend often to be combined with the Wilson/Krell combos, (more brightness into your system) unless of course, that is your prefered sound, in that case just go ahed and remember is the music that matters, enjoy it.