For S550 alignment, the best guy I found was Don Wolf at the Beechmont Anderson Tire Discounters. He is the mustang whisperer when it comes to alignmnent. You will need the Steeda camber plates as well (or any brand, fpr that matter). I did all the front bearings that Steeda offers for the...
I did Factory GT350 front springs and GT350 roll bar with all the steeda bearings and extended ball joint/bumpsteer kit up front. Love the ride and turn in is sublimely neutral
I have both BMR and Steeda items in my build, and selected each based on their merits. No problems here with either, other than the money I lost on the Steeda rear shock mounts that they said would fit Bilstein B6's... and didn't.