Yes, 10MM is king.
First, start reloading 10MM. Same bullets as .40 Short and Weak with dozens of shapes and varieties available. In addition, several good rounds are available from Buffalo Bore, Underwood ammo and Double-tap.
Recoil out of the GLOCK platform is not an issue; much like a steel 1911 shooting .45 auto....nothing to think or worry about.
Other advantages to the GLOCK platform, besides being able to tune and maintain the weapon all-by-yourself....:
1. You can run either the GLOCK 20 or GLOCK 29 with a .40 barrel (same magazines) and .40 is WIDELY available for less money (if that is an issue) at Wally World.
Cost for a barrel is about $115.
Also you can run with a .357 SIG barrel, 9X25 barrel (same magazines)
again, offering a choice of 4 calibers with a simple barrel swap that takes 14.5 seconds.
The GLOCK 29 is my favorite handgun of all time. It will take G20, 15 round magazines as well.
2. At around $500 to $600,, nothing is a better buy. Buy two.
3. The Glock 29 and Glock 30 (.45) have the exact same frame and ejector. So you can also install a 10MM top or a 45 TOP end on either frame to convert calibers. Another change that takes only 12 seconds. You will have to change magazines.
4. Advantage Arms makes a .22 top for these GLOCKs as well.
I reload so ammo costs are not an issue.