Rear brakes dragging. Should I rebuild the calipers?

[Jeffd]

2000 Boxster S, 130k mi. The rear brakes have been intermittently dragging since before I owned the car. They get very hot, smell like burning brakes, and have worn the rotors pretty bad. I've got all of the parts on hand to replace all 4 rotors, all pads, braided stainless steel hoses, and replace/bleed the fluid.

Should I hold off on the work and order rebuild kits for the calipers? Or should I install what I have and hope it addresses the problem? I guess I'm asking, how likely is it to be a caliper seal over contaminated fluid/air in the system/collapsing rubber hoses?

Thanks,

Jeff