Anyone got any views on Force 10 4 pot calipers / 13" slotted rotors from http://www.performancesuspension.com as a front brake upgrade (quality any good, are they actually good / worth having over 12" rotors with 2 pots), as an alternative for hunting for individual parts, slacker that I am?

Just another company capatlizing on folks laziness. It is easier to buy a preassembled kit than to build it yourself. My C5 brakes are just as good if not better and total cost was around 400.00.

Agreed Dennis 68. Unfortunately for me I'm new to (American) cars and don't know what fits / can be interchanged with what, and the difference between a B-body tall spindle, and if a 13" rotor from a corvette fits straight on a 5th gen 2" drop spindle etc. Car and (motor) bike terminology is as different as American and English to me (especially being the associated with the latter).
Your C5 conversion and accessories are pretty trick. Are the C5's 4 or 6 pot calipers?

Anyone got a blow by blow idiots guide to cheap(er) conversions than a off the shelf kit - the blazer rear disc info posted was pretty easy for me to comprehend!