Don't buy a sig (or sig clone) in .40 for your first pistol. Speaking from experience
I would suggest starting w/ 9mm, in whichever platform fits you best. Many other will say .22, but 9mm worked for me (ended up with a Grand Power in 9mm). .40 didn't, especially with the high bore axis of the P226 frame. I can only imagine the x25 round to be similarly punishing for a new shooter in terms of snappiness. This gun seems like a very cool opportunity though, if was to buy a Sig clone again I would go for the x25 over .40, if nothing but for the unique/cool factor and price of ammo.
Tough to get a nice blue on aluminum. My NP58's frame and slide didn't match up perfectly, though it sounds like they've improved their finishing quality across the board. All in all, well done CanAm.