I can sell you a set of bolt on flares that are made for a 2 door Mk2.They will fit a 4 door but you will have tocut the rear flares around the rear edge of the doors and I would sugget you glass up some plates to strengthen the cuts.
Others have done this conversion. I do not know of anyone who makes them specifically for 4 doors.
Geoff Wade
(03) 9705 2791
0417369996