Did some numbers, and looks like fender mods wouldn't be needed unless you wanted to go as low as their BRZ.
18x9.5 +30 is equal to 18x10 +38, (technically 1.65mm different. Equates to 0.064" more poke on the +30) which is a package being sold now. See link.
http://www.ft86club.com/forums/showthread.php?t=15458
Looks like it would be feasible with a bit less aggressive drop with 225/40 up front and 245/35 on the rear. Camber set to -1 front and -2.5 rear.