Not keen on the HK, the grip just doesn't feel right for me. If I was in the market for a .45, I'd either get Colt's or Sig's 1911. Probably more leaning to the Sig in that regards, thing is stupidly accurate.
If you are able to correct the recoil after each shoot, Sigs grip don't see very good, but them again I'm not as well versed, hmm are you fond of shot ranges?
Sig's 1911 uses the standard government frame, and the magazine is single-stack so the grip is 'thinner.' It fits well in my hand, and least. Shot range is not a primary concern, and the effective range of a pistol is more than enough for any CC incident.