I have posted before on this topic, even if the calipers were free - you would find out that by the time you machine custom parts, wait to order parts, buy rotors, special hardware, lots of head scratching, re-machining when parts don't fit - you will be WAY better off just buying a BBK off the shelf.
Trust me I learned this the hard way.
And so did my "friend" who has the machine shop - he told me next time I come to him with a "project" like that, he will throw away my so called "great deal" parts and just buy me a stoptech or brembo kit - he figures he'd come out ahead, ad I believe him.
Sell those calipers and put it towards a proper kit - you'll thank yourself.