I can vouch for CW's seals and stainless pins, just done my front uk calipers a couple of weeks ago, fantastic kit, needed my compressor to blow one of the pistons out but the seals were really easy to change. Turns out the passenger front was binding, works a treat now, car feels so much faster (that maybe because I haven't driven it since about August though, my hdi 307 isn't exactly what i'd call a fast car).
I bled my front and back brakes and fully flushed them through with new brake fluid, i used 2 litres but probably didn't need that much.
There are a few threads on here about caliper refurbs, most important thing is make sure there is no corrosion on the pistons or the bores, and keep the pistons clean when reassembling (use brake fluid as lubricant).