sounds good! i haven't done the 2 jug system yet, but have thought about it. i've seen here on RCU that most will plumb them to the wall of the box and then just manually take which fuel you want and insert it into the fuel pump. different colours for different fuel. then reconnect so it seals it from the air. seems simple enough to me. there are a few good ideas in this thread, that is for sure. if you have time, take a read back through it.
i presently used a 18ah battery from a UPS, bolted the wire connections and mounted my fuel pump on the outside of the box. i purchased a Slimline Boxer pump. so far, it works in my basement transfering fuel back and forth. haven't gone out flying yet, so that will be the true test.