The Sigs are excellent pistols, but the 45ACP can take a little getting used to for a
beginner. Recoil ref. 230gr. hardball vs. 185gr., I think you'll find the 185gr. to be a
little lighter on recoil, but not a whole lot. All things being about equal, and the gun is in
this case, the lighter bullet weight will recoil less. However, in this case we have different velocities to consider too. The 185gr., though lighter, has a higher velocity,
and it was my experience that I didn't feel too much difference in my Colts.
You might want to try and locate some target wadcutter ammo for 45ACP. That will
cut the recoil down for practice work.
BTW, good move on getting the 22 to practice with too. Also, as noted above, save that
brass. Even if you don't handload yourself, you may be able to get a few bucks for the
brass.

Note: Found a load you might want to try. It's made by Federal, load no.: GM45B.
It's a 185gr. FMJ-SWC Match. Velocity @ 780fps.
You should find this a little easier than using the 230gr. hardball. Good luck, and keep
practicing.