I have a 226R SCT as my nightstand gun:
I also have a German triple S/N 229R with an ilaflon finish, and a NIB W. German Nickel 228.
The frame of classic series SIGs is aluminum or stainless and won't rust. The slide of newer guns is stainless and nitron and ilaflon both are pretty good finishes so it won't rust either. What will rust like crazy are the grip screws but replacement with an aftermarket version will cure that.
You can find a ton of 228 police trade-ins right now for ~$400. Many people feel the 228 is the best pistol SIG has ever made other than the 210. However, 228s do have carbon steel slides that can rust. However, $400 for a trade-in + $175 for a modern finish that the gun might need anyway and will prevent any rust isn't a bad deal!
And you can get a super decent 1911, an STI Spartan, for ~$630.
Edited by leftnose - 1/11/12 at 11:00am