Hi
The FRP was originally fitted with Alcon discs at the front, not bells and rotors. Although the bell and rotor option is now considered to be the best replacement these days (around £500 for initial setup).
The original Alcon discs are no longer available, but when you could get them you would be paying around £260 (FOR ONE).
The discs you have ordered for £80 will not fit and have been wrongly listed. Good luck fitting them
It's not really clear if you are selling the car or not, but my advice would be to get the mechanical bits well sorted, if I was buying any car which had been sprayed over just before a sale I would be a bit suspicious. Probably better to save your money and let the new owner decide on the quality of paint job.
78k is not very high mileage and an FRP with sorted brakes and up to date cam belt change should sell OK
Paul