I had a full Sachs OEM clutch/DMF/bearing & bolts delivered from David Hawthorne at SERE motors (Seat dealer) for my BKD, was about £475 last year.
Worth ringing your dealer or TPS first.
Looking at 4-5 hours labour if not fitting yourself.
Buy it somewhere reputable as you may get a remanufactured kit or poor quality DMF if you buy from some ebay sellers. I know GSF carparts, EuroCarParts etc do good quality kits.
I'd stick with DMF on a 6speed also, not a SMF conversion.
Darkside Developments do uprated ones since you're looking.