As far as 10" wide rims on the front they will not work without modifying the car to enable the wheels to turn without rubbing the wheel wells. Even the GT500 cars only have 9" in the front.
Hope that helps a little bit. As far as the wheel spacers and all of that, I can't help you there. I'm at a loss with that stuff myself.
I confirmed with several vendors that the 2010 has the same bolt patterns as the 05-09. Was about to pull the trigger on the below but they don't make them in the mustang bolt pattern on the 8 inch wide rims. They do for the 9.5's though. Go figure :-( Can buy rears but no fronts... I'm still looking for that right set.