Novak Conversions Jeep Wrangler TJ radiator

Brake pad problem

There aren't any 02 and older TJ rear discs. They started in 03 when the Rubi was introduced.
Brakes situated thank u guys.
Thinking ahead. May replace all calipiers with new. Blaine notice the spongy brake peddle. Should I change master to accommodate the Ford calipiers in front?
 
Novak Conversions Jeep Wrangler TJ radiator