For HK, the compact category would be the USPC or the P2000, the sub compact are the ones you mentioned plus the P2000SK. If you like the ergonomic feel of the grip for the VP9SK/P30SK then it would be a choice of hammer and striker. If you like the traditional grip of the USP the you have the P2000SK. All are good and it will be a matter of personal preference. Rent and shoot them all and see which one you do better with.
I carry the P2000SK but I like the grip of the P30SK but I shoot the P2000SK best, go figure. Good luck and let us know what you got.