If you don't have giant hands, I would look at the newer P30 or a different gun altogether (especially if you plan on putting a rail-mounted light on it since the trigger guard extends waaaaaay forward of the grip).
If you want an upgrade from both the Glock and HK, look at a Sig
I got to handle an HK 45 at the range and it fit me like a glove. Grip was beautiful.