To do econo vented rotor for $50 , I swapped to early S197 V-6 brakes, by using V-6 caliper brackets (free in trade for GT brackets), my calipers (same ones on V-6 and GT), cheap $50/pair Ebay drilled/vented V-6 front rotors (V-6 rotors are smaller diameter=lighter, drilled=less), plus I put a resurface cut on them (you could reduce diameter by 1/4" or so also, down to pad wear area). Then, I took used/worn street brake pads (free) that were down to near minimum (less material=lighter, still safe). Basically, you pay $50 and may save a few pounds per side, but MOST IMPORTANT your aren't sacrificing safety (you have V-6 braking performance, which is still better than all previous model Mustang GT braking).
Also I found that a cool way to gain caliper-to-wheel clearance is to run the worn to near minimum brake pad on the outside and use a new pad on the inside. The caliper is pulled in all the way and completely safe.
In all fairness to Fox-body, SN95 guys and almost every disc brake car before that, you already have light brakes in the front! Pick up an aluminum caliper from an S197 and then pick up an iron one from a Fox body (or any other year from any other manufacturer).
So many other places to save weight on an S197. If you are drag-only, drag brakes are fine, but if you drive on the street, take weight off elsewhere.