I shoot 9mm using Rem +P cases. I don't load to +P pressures, as I don't see the need to (my load is 6.5gr HS-6, 124gr. Frontier FP @ 1140fps). Just because it says +P on the headstamp, doesn't mean you have to load it right up. I usually use Win brass, but swapping and using a Rem +P case shows very little difference over my chrony.
I find very little difference in regular Rem 9mm brass and Rem +P brass, they weigh the same, thickness appears about the same. It my be stronger, but I don't push it. There are many published loads pushing 115gr. bullets to about 1250-1300fps with proven powders.
Most of the 9mm major guys use HS-6 or the VV powders. Power Pistol will also get you up there. Work up a load and be safe.
I'm of the opinion of RePete, why? If I want 9mm +P or +P+ I've got lots of factory ammo that I know is in spec. I keep my loads to the book.