The best way to go is to buy a system. Tell the supplier what you want to do. IE: disc front & drum rear with the booster/master mounted under the floor. I have done several of these and used a 8" dual diaphram booster with a dual master and a proportioning valve. My supplier installs the residual valve in the MC.
Lots of opinions on this subject but this has worked best for me and my customers are happy.
Fred
