Under dash MC pedal set

If you go with the remote mount reservoirs you could put them in the engine bay and route the hoses thru the firewall.

Brake balance bars aren't for sissys. They cause more trouble in set-up and adjustment than do proportioning valves by a large margin.

There are also bell-cranks in OE use that turn the MC to one side or the other. Early Broncos with power brakes turn them ~30° to the left. I seem to recall that Dodge vans in the 70's used one that turned the MC 90° to the right, but perhaps it could be flipped over to turn it to the left? Or could build your own if you have that level a fab skills available. Most all of these are because of booster clearance issues, but that doesn't mean that you couldn't use them for manual brakes.

Early Bronco part, can buy it new from most of the EB vendors like BC Bronco's, Duff's, Tom's Bronco Parts and the Bronco Graveyard:






In searching for pics of the Dodge van part I found a not terribly good pic on ebay of a bracket that moves the MC up:


Custom fab'd bell-crank from the H.A.M.B., the single shear mounting for the link isn't a great plan:




Looking for further for pics of the van part I found that Kugel makes this:
http://www.kugelkomponents.com/zencart/index.php?main_page=index&cPath=4_5


Found this for a GM RV chassis, so potentially all Class A GM motorhome chassis are donors: