I think the Sim Audio i-5 recommendation is not a good one. The i-5 is not very versatile sound-wise, if you wish to cover a large variety of music.
Even though you wish to have more power, I would suggest you have a listen to a Naim Nait 5i. It sounds subjectively much more powerfull than it's rating imply, and is much more refined-sounding than most of the higher power competition. The Mac 6450 is also nice (used to own this one too, with the Sim I-5). Again here, no contest with the bright-sounding I-5. Its the Mac hands down, and you have ( horror! tone CONTROLS!) knobs to rotate past the cost of expensive interconnects to ,'tailor'' your sound!
Good Luck !