BIGGRED.CO.UK is the daddy of all things brake wise and very reasonable rates.
Just done my front pair(2wd sapph) for less than £30 in seals, but needed 2 new pistons, £9 each, so still very good.
He does of course do recon yours/exchange etc etc etc, with an ace FLEUROMPOLYMER COATING, that resists everything short of a full on nuclear assault!!
Tel 01905 428793.
tabetha