I got my set of robiwil here for a good price.
they were mk3.5 cabrio hubs (4 stud)
mk3 gti (280mm brake version) calipers and carriers
brand new g60 disks and pads.
Bolt on job. Had no problems with the caliper touching the wheel. No need to run thinner pads etc.
Much better braking over the 239's!
I have kept my standard brake master cylinder but after speaking to RJ I think I might upgrade it as this should give me less pedal travel.
budget for lazer wheel alignment, new bearings, track rod ends and other bushes you might need to replace.