Handloading allows the shooter to tune their loads to what they want so 10mm or 45acp, you can't really go wrong. While I have G23 in 40s&w and use it for my CCW piece, the 10mm in something like a Glock G40 with a 6" upper would make both a great range and hunter piece. If you're into a red dot system on your piece, the G40 MOS version is killer.
While I don't own a G40, I actually made one long before Glock did. You see, they took my idea I developed way back in 2004 and copied my longslide Glock 10mm/45acp; my custom G20/21L.
You see, I developed a G21L 45acp longslide version first in early 2004 using a custom 6" German steel slide and a 6" Jarvis 45acp barrel. Later that year, I got the idea of developing a custom 10mm from it and after a number of tests, I discussed the possibility of a custom 45-10mm conversion barrel with Kevin, owner of KKM Precision. He agreed and made me the first ever KKM 45-10MM conversion barrel for my custom longslide Glock in the fall of 2004.
With it, I made up my G20/21L, the world's first longslide Glock shooting both 45acp and 10mm. Since then, I've worked with JR, owner of Lone Wolf Dist., on his excellent line of SS longslide conversions in multiple calibers but this slide is steel, not stainless steel, and predates by a few years all of the Glock longslide conversions.
I've run over 9,000rds of hot 10mm through it and love how it shoots. The extra sight radius length coupled with the added 4¾ oz of weight at the muzzle make for a solid, performance shooter while the 1.6" longer barrel allows magnum powders like Power Pistol to develop significant velocities. Even with my 'nuclear' level 165grn 10mm loads pushing 1,589fps with a whopping 925ft/lbs of muzzle energy, my Glock, with it's low bore axis, has little to no muzzle flip; rather a strong push more straight to the rear. This makes the platform a great hunter as followup shots are straight forward.
It's now been updated from just a hunter to a more competition version with a hardchromed slide, magwell, and slicked up action and custom trigger. It's a joy to shoot steel plates at 200yds, standing with a Weaver stance, as configured below. For walking in the Rockies as a protection rig, I simply remove the magwell to reduce carry weight. Then I load it up with 17+1 rds of my handloaded 180grn hardcast handloads producing 1,479fps or 200grn hardcast producing 1,383fps. With it I'm ready to deal with any 2 or 4 legged issue as I have 3 times the ammo of a revolver on board and much less muzzle rise than a revolver. All in a package that is slimmer and weighs less than a 6" S&W 686 357mag revolver with only 6rds on board.
However, the OP is leaning towards a 1911 style so I suggested to him he consider one of Springfield's excellent 'NM' s/n 1911s in the classic 45acp. As he handloads, he could work up some great 200grn loads for one and have a classic 1911 to enjoy for a lifetime at a reasonable cost to shoot. I have both a Mil-Spec and a Range Officer and both are excellent.
With a forged frame and slide, excellent accuracy, and super reliability right out of the box, I can't recommend them too highly. Both mine will eat anything, ball, plated, coated lead, HP, or even some old Speer Flying Ashtray ammo, they just keep on shooting.