whats wrong with your calipers?
theres a good company called big red in worcester that can refurb calipers and paint/enamel them in almost any colour.
they did my uncles camero carrera calipers which were seized full of rust. http://www.biggred.co.uk/
I bought a brand new caliper last year from Mr F, think it was around the £90 mark and came complete with pistons and seals. At that price, its a no brainer