You are well covered for amplification. If you're really looking for an audible sonic upgrade it's gonna come from speakers. With the ones you have its gonna be tough to beat without shelling out some bucks, but I'd do that before I'd spend it on amplification without a 2nd thought. If I had your money I'd be looking at Salk, Revel, KEF, RBH... there are other makers of truly great speakers out there. Any one of those might have one you prefer over your Focals.
You really do already have a nice rig. You're well at the point of diminishing returns, especially with the electronics. Not a bad problem to have, lol.