I just finished upgrading my G20 to serve my purposes. See photo below.
Added:
22 lb. guiderod spring
Lone Wolf Tactical 5.15 Barrel (Non-ported)
Extended Slide Release
Slug plug
Pacmayr Grips
I did not add the extended mag release. I didn't want the extra hanging off the gun. I opted for the non ported barrel to not have flash in my eyes and to satisfy the 5 inch requirements for hunting purposes. I ordered some 180 Buffalo Bore in which two shells out of one of the boxes were too fat and would not fit into the LWD barrel or the factory barrel. Looks like I will go with the Double Tap 200gr WFNGC Hardcast for hunting and the DT 180gr. Controlled Expansion JHP for home protection.