From the manufacturer:
There are plenty of adverts about reclining seats for Minis, which can be misleading. Our Suffolk seats come complete so that all you need to do is unpack it and bolt it straight in the car. Others on the market need additional subframes and headrests. On our seats, everything is included in the price shown. All you require are two 7/16th AF spanners to undo the two nuts and bolts on each seat to replace your old units. We designed the base part of the seat frame to look identical to your original seat, which allows easy front to back movement on the plastic slides on the carpet. This seat is made out of high specification Automotive vinyl. Rear seat cover kits to match are also available. The seat comes with a twin post headrest which you can slot into place quite easily.
Special order, may be subject to a $25 handling charge; lead time required. Additional colors available; actual colors may vary from those shown due to monitor display differences.
Priced and sold each.