Rimmer Bros in Lincoln do the H type clips that retain the pins on caparos. Part number QP2740. Dont know about the pins themselves but they have a website you can search.
Have you applied a smear of coppaslip on back of pads and also on edges where they bear on caliper housing? Also, the pads are usually a tad too large for the disc and can rub on the outer edge of the disc. Just needs a little chamfer to be applied to the top edge of the pads with a file. ( all in Dave W’s book) Hope this helps.
