I know this isn't the answer you're looking for, but you can't go wrong with either of them. Both are reliable, well-built handguns.
The P99 Compact is a bit rare, so it should appreciate in value and be a unique carry piece with some character (if that interests you at all). I also like how it functions like a DA/SA gun. But on the down side, spare magazines for it will be hard to come by.
The PPQ is more modern, ergonomic, and one of the best striker-fired triggers of all time. Solid handgun all around.