I went with the Glock 27 (and 22 & 23) and don't find the recoil to be a problem. Later I got a Lone Wolf G23 40-9mm conversion barrel that lets me shoot 9mm in the 23 and 27 (reliable but not recommended for self defense, just range use). I'd choose the G27 again if I had a "do over".
40S&W is easy to find, even during panic buying, which is something to consider.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
US Army 1966-69, VFW Life Member, Retired Geek