testing callipers

hi, im upgrading my 1.1c brakes to gti callipers and carriers. iv got a few sets to work with..what should i look for when deciding which set to use?
         thanks,matt

I'm no expert on callipers but say the ideal would be to check the pistons/bores for any wear and replace any seals. Other than that should be straight forward. Oh and if any bleed nipples fitted check they;re not seized before you fit the callipers!