Uh, what is it FOR?
P229 is more compact for carry than P226 which has more butt and sight radius for easier shooting. Two tone is cosmetics, your call if they will sell you one. Rail, ok if you need a searchlight, but I don't know how many SIG Sauers are available with them.
Do you have an ammo budget for .357 SIG? It costs a good deal more than 9mm econo-ball, don't know how it compares with .40.
First handgun purchase? VERY first?
.357 SIG has the loudest blast of any service pistol, close to comped Super, and appreciable recoil. Not what I would recommend to learn on.