SJ413 brake masters

[3VILC]

So the biggest mission on my list to get the beast usable, is the brakes fairly well need a major overhaul. I've got everything to rear disc it, got a total of 6 calipers so hopefully 4 of those arent seized and rebuildable. The Subaru master swap seems to be popular and obviously easier to get and less likely to be stuffed than an SJ one. But what about the vacuum booster?this is obviously well rusted from the leaking master and leaks vacuum too. Do any others fit without too much mucking about? Or is a complete vitara/escudo booster and master able to be swapped in? Off road only so cutting drilling etc no problem
Cheers guys