i ve built 3 ka turbos all of varying power levels very nice cars, handle well they will suprise alot of people on road and track!
rear discs are simple bolt drums off and bolt focus 2.0 stud axles on and focus hand brake cable
master cylinder you may have issues with, when upgrading the brakes!
id use the ib5 box from the ka they work pretty well and you keep all original mounts etc!