I personally would use genuine BMW parts if the clutch judders or anything on a pattern part any small cost saving will be lost when the gearbox has to come out again........
While in there it is a good idea to replace the crankshaft rear main oil seal....if it starts leaking later as they sometimes do, it will ruin the new clutch and involve the gearbox coming out again to replace. Also replace the clutch release/thrust bearing as these can become noisy later.
More info here:-
"The next step is to replace the rear main seal. This seal is an important one as it seals the gap between the crankshaft at the engine block. If this seal were to fail, it would start leaking oil all over the ground and likely onto the clutch plate as well, rending your clutch basically useless. This is one of those 'while you're in there' items that really should be replaced." Pelican Technical Article: MINI Cooper - Clutch Replacement 1320 Optional Related Services
Clutch Kit Supplied & Fitted - R53 £540
"We recommend replacing the rear main oil seal while the gearbox is out and the clutch is off. This seal sits around the crank behind the flywheel and often leaks engine oil over time, sometimes the leaking oil can get onto the clutch plate / cover surface causing premature clutch slip and eventual failure.
We can fit a genuine MINI replacement crankshaft oil seal while the clutch is off for £54
As part of the clutch replacement procedure we have to remove the front sub frame, if your front bushes are worn this is the ideal time to upgrade your wishbone bushes to new Superflex poly urethane bushes saving you £84 over the regular replacement price.
Remove and fit new Superflex front wishbone bushes for £132" Clutch Kit Supplied & Fitted - R53. MINI - Servicing - Repairs - Tuning - Parts - Spares