The Glock 20 is a great all purpose handgun. I have several G20SFs and a couple of G29s. Including a G20 Longslide for hunting and a Mech-Tech Carbine conversion unit. I am dedicated to 10MM. (and .40)
My personal opinion is you should reload
if you're going to shoot the 10MM much more than casually.
Of course, reloading 10MM will involve an investment in powders (Longshot is my favorite), boolets, large pistol primers and I use new STARLINE Brass. Buy in bulk; keep good records.
Being able to run .40 is also another bonus of the G20. (as well as .357SIG and Dillon 9X25)
Those 45-10 barrels are hard to find. Stormlake sells them. Expect to modify the extractor to run acceptably.