Speakers for Sonic Frontiers Power 2 Amp?

I just purchased a Power 2 amp that should arrive any day now. I'm looking to replace older but decent sounding Mirage M7si speakers. I have a modded Jolida JD-100 tube cd player, and a TAD 150 Signature tube preamp. I'm considering some Usher speakers and contacted Stan at Usher Audio. He stated the 6311s need damping factor > 100 but the Power 2 is rated for damping factor > 50. This relates to bass control I guess. Can anyone having experience with this amp and share their opinion with speakers used. I'm looking for full range speakers (used around $1000 > $1200) that the Power 2 can run properly. Thank you. Paul