I had one and they move a lot of fuel. Use really good fitting and really good hose.
I would suggest a tall thin tank mounted above the bed but so that you can see over it, make the tank go from all the way on one side to all the way on the other side. Make the coolant connects on the drivers side of the truck with the fuel connection there also. Make sure you have a vent on your tank. And possibly a return connection.
I would use 1/2 in Pex Line from Home Depot or Lowe's for both the fuel line and the coolant line. Get Push-Lock to Flare fittings so that you can remove the ends. To get a good seal heat the PEX line and use the back something to widen the PEX Line then force the PEX over the Push-Lock fitting. This will give the best seal without hose clamps or metal lines. Wrap those line together with electricial tape and then insulate with plumbing insulation and wrap that also.
For the engine bay get a big FPHE, 26 plates would probably be good. Get two filter mounts from the local semi truck parts location. Make one for diesel and one for Veg. The veg gets wrapped in heater hose. You will have to make new connections for the fuel lines. The simpliest way is to make the fuel pump suck instead of push into the fuel filters. (It is a very strong pump). TO do that you will have to make the return line that normally goes to the diesel fuel filter return to a common connection. At that connection have the diesel return to the diesel tank and the veg return to the veg tank. Or you can loop the veg back into the veg fuel in line. For the fuel to the engine and the return you will need two selector vavles. I like the large greasecar valves. Not the Hydroforce ones! The fuel from the diesel tank will go to the normally open side of the fuel selector valve and the Veg will go to the