My local shop had to order me one, but then again, I had already handled one and knew what I wanted. A/S models are hard to fine on shelves. I do not think many are being omported. If your store has more than 1 regular distributor, he should be able to get U one.
I just held them together. The P99 is a little thinner in the grip, but the angle is different from the Glock. Its also much mor ergonomic in shape. Trush me, U will like it. There are 2 back straps too. So, if you have very large hands, U can swop to the biggest one. It comes w/ the medium one installed.