I have a G20 and did have a G29. The G29 has too short of a barrel to get any potential out of the 10mm. I could not find a reload combo that could get the G29 up to 10mm spec. You would be better off getting smaller G27 with more rounds. The 10mm needs a longer barrel. That said, the 45acp is low tech and doesn't need speed for it to work so you may want to go that route.
"I'm a good guy with a gun" What do I care if I give up some freedom or rights?....The Goverment will take care of me. This kind of thinking is now in the majority and it should concern you.
"Ask not what you can do for your country, but what free entitlements you can bleed from your country"