The discs can be made for the rears as well to match and mine are in hand The engineering firm buys in the discs from Delpi Lockheed or AP and then machines them.
Really pleased with the brakes. There has been no grinding, squeeling or any problems at all so I'm delighted. I accept that this mod isn't as cool as £2500 per axle Brembos but I did discs, MB pads and fitting for under £250 which I reckon for the looks alone makes it a good mod.
I've only look at C Classes but W203 C320 Discs are about £120 all in ie. less than MB standard discs. W203 C180-200k are about £100 and W202s are less than £100 the pair.