Check out Master Power brakes
www.mpbrakes.com also Engineered Components, Inc.
www.ecihotrodbrakes.com for information on boosters and combinations.
Just a thought....are you sure you want to go the power booster route with your system. I'm very happy with the mid-70's Corvette manual Master cylinder, in both disc/drum and disc/disc configurations. I have power discs on my hot rod truck and find that they are a bit twitchy. My 54-3100 manual brakes with front discs are very predictable. The underfloor power booster/crossmember interference issues are something to consider. Check out these sites as well as
www.911brakes.com and you might get a better response if you included a little more information on your application. Hope this helps.