i bought mine from burtons
but this was AGES ago
cost for the whole lot was in the region of about £300 (but we are talking at least 12 years ago now)

pedal was rock hard and it didn't feel right, even though you could stop it was never as easy as keeping the abs

adjustable pedal box was a good gimmick, but i needed to have a remote servo (and then the engine went smokey smokey and caught fire but thats another story for another day) to get enough pressure through the brake lines
or legs like tom platz