Dawg,
My .45 Colt cylinder measures 1.620"
My .357 cylinder measures 1.628"
My .22 LR cylinder measures 1.627" (didn't measure the .22 Mag Cyl but should be the same or very, very close).
Remember, the cylinders are recessed for cartridge case rims, so overall length will be less. I usually try to keep the OAL at 1.600 or less for loaded rounds.
I'd probably go with the .44 Spcl. More lattitude with overall length constraints. With that said, I load the 270 SAA and the 300gr RCBS with the crimp over the front drive band (powder reduction to compensate for reduced case capacity) in the .45 Colt -- kinda funky looking, but work fine.
I just got the .22 (5 1/2" bbl w/.22 mag cyl)-- absolutely love it -- don't know why I waited so long.
The .45 Colt is great -- 300gr RCBS SWC GCs at 1,130 fps hit virtually same POA as 270 SAAs at 900 fps (both bullets from Mt Bullet Works). With the 4 1/4" barrel, it makes a great "Packin Pistol".
I'm sure you will be happy with either one.
Paul