1. Any CZ. It's what they are made for.
2. Ditto the 9mm Glocks. Mine shoots +p+ like its spitting out bb's. No recoil, no malfunctions. No noticeable wear-and-tear. Just gobbles up +p+ like it's candy.
3. HK's are all designed for +p+ ammo.
4. I hear the Beretta is fine too, but I do know less about them than the others.
5. I've heard of several folks using +p+ ammo in FN Hi-Powers without a single problem. The SAS loves theirs, from what I hear.
6. Sigs will generally be ok, but I have heard that the p226 slide will crack with too much +p+ use. Should be fine for many thousands of +p loads, though.
By the wayI considered the .357 SIG before I bought my G19.
Between the two, 9mm is the way to go. You can find 9mm loadings that closely mimic the .357 SIG, and you can find cheap ball ammo, too. You can find submachine gun loads that push 1500fps with a 124gr slug, and a number of other interesting military surplus loads.
You can find 9mm ammo everywhere, from hardware stores to Wal-Mart. Its everywhere, and it is cheap as dirt. Cheaper than anything short of 22lr.
I found the choice of 9mm over .357 SIG to be a no-brainer for me. A p229 in .357 SIG would be fun and powerful...but I see no real advantage over my G19 w/+p+ ammo.
-David