I have a 29SF. I put a LW standard barrel in and a 21# spring/Non captured recoil guide rod. I also like the Pearce finger extension on the mag for grip control. I added a set of night sights with a slightly wider rear notch. I don't handload. It functions perfectly with Blaser 200 TMJ, and for the nuclear loads. In fact, both the Buffalo Bore 155 DPX and Double Tap 230 HC feel like shooting a hot 9mm round in a G19. The 29SF carries as well for me as a G23/G19/G36 I've had, and shoots as flat as an M1 Carbine to 75yds and beyond ( I've hit a good number of Clays at 75yds, missed some sure, but was still "minute of coyote",ha)
I "may" get a G20 Gen 4 later in life, when the madness has subsided, and it will. Even though I have big hands, I prefer a slimmer/smaller feeling grip ( decades of 1911s will do that to you!) The G20SF didn't feel that great to me, and since I hit so far out with stubby, I use it for full time carry/woods gun/carbine replacement. I think, however, for your purpose, the Gen 4 G20 will feel the most familiar to you, and you can't carry anyway (well, that's up to you, its your life, protect it as you see fit) I have used a lot of handgun rounds since I was 16 (my first was a little Browning .32 my Great Uncle traded me for a shotgun he liked) was a die hard .45 ACP fan (still am) but when I saw how flat the 10mm is, gee whiz, I'm happy! BTW, both of those BB and DT rounds shot completely through two freshly killed hog heads in a bullet test! Its also "rumored" that the craters on the moon were caused by drunk Red Necks shooting their 10mms in the air!