I'd trade for the P226. That sounds like a pretty decent deal. What condition is the 226 in? If it just has normal wear on it, you're fine. The thing about SIGs is that they can be shot for years and years and still have enough left over for another generation of shooters. Single stack for the given size of the P6 is unreasonable by today's standards. Move on up a notch!
The P228/P229 is thicker in the slide than the P226, but is .5 inches shorter if that means anything to you for concealed carry. I find that they handle almost identically when shooting.
The P228/P229 is thicker in the slide than the P226, but is .5 inches shorter if that means anything to you for concealed carry. I find that they handle almost identically when shooting.