Couple of other things, if you are going to use two clunks, wire them to each other to prevent tangaling, otherwise just put a Dubro tank in and put the filling line into the front extension with a Tygon tubing extention at the front of the tank, you can get 3W filling bungs as shown below, also do not forgett to barb the copper pipes as they will slip off otherwise, I use soft paper clip wire soldered onto the copper internally and externally and zip tye the tubing behind the barb, see pic below.

Mike