Custom building for the 6.0l v12 bmw 760?

my bother gave me his 04 bmw 760i it has a 6.0 v12 it got 98000 miles on it any ways i am not in to European car i in to classic American muscle big-blocks so on any i got this car i want to do this car up right bigger cams bore .030 over forged stroker crank h-beam rods forged pistons head work porting and polish headers so on dose the aftermarket have this stuff for this make of engine or should i just drop a 502 in it and be done with it