It all depends on how you make it I suppose. I would try and avoid cutting the keg apart like I did. I would simplify it and get away with welding on a couple bungs and run the external pump. You need a fuel return line and breather as well as the fuel out + a fill cap. I reused a power steering fluid resevoir cap for my fill.. says Toyoda on it. I would try a different route if I did one for you since you don't already have a Tacoma pump like me. I did it for free99 minus consumables, wire, gas , electricity sanding disk and time. It might be a pretty penny starting with nothing because you have quite a list of things to buy. I do have a hook up on kegs though
