Master cylinder swap

I also recommend switching to a 2 bolt aluminum master cylinder, for better choices, future rebuild, and much lighter. Requires an adapter plate (~$70). Haven't read of anyone just drilling holes in the firewall, but maybe. For manual discs, get a small bore diameter. You can find suggestions by searching FABO. You could install power brakes, but requires brackets, adds clutter, and many say unneeded for an A body.