Ya gonna struggle mate, the FRS Discs are 330mm, I'm in the process of fitting em on my track car, and due to the way you have to mount them they dwarf 300mm Discs...

Have a look on my thread (Click under my sig) there are some pics on there.

For the cost involved if you really wanna retain the MO's i'd go for the HiSpec 4 pots, that are made for 16" wheels.