Re: 8.8 swap
Most shops around here are under $200 to do the swap, including the pinion flange change. Unless you get a rear end from a 2011+, then you need to change to the cobra flange so that your driveshaft will mate up to the rear end.
Make sure you are getting a rear end for the S197 though (2005+) because you can't put different 8.8 rear ends on the Mustang S197. It is a three link system. (2 lower control arm and on upper control arm).