Can i fit hubs brakes an wheels from mgf to cox coup an can rear sub frame be fitted with eng/g/box or is it big job thanks

Nope, and yes it will be a massive job

The brakes (rears at least) can be fitted to Mini hubs and combined with Metro Turbo fronts will give you as much braking as you can use in a Coupe (enough to lock all four wheels).

There is a modified subframe available to fit a K-Series to a Mini which will likely allow it to be fitted to a Coupe but not necessarily as the modified subframes for Minis usually try to keep the engine forwards to clear the Mini bulkhead whilst in a Coupe the bulkhead is in front of the engine so the engine wants to go further back. It would probably be easier to make a custom frame based on a Mini one than to try and fit the MGF one though.

MGF wheels use the older 3 3/4" pcd rather than 4" on a Mini but if you're set on using a different style of wheel you can get modified drive flanges for the Mini to allow fitment of different wheels. Personally if I was shelling out for them though I would get a set made for 4x100mm studs as this seems to give a wider choice of styles, sizes and offsets of wheel.

Iain