GJ, the Facet fuel system goes like this, the 16 oz. has the vented line coming out of the aircraft, it feeds the 40 oz. Dubro which feeds the UAT (or hopper) which feeds the fuel pump. This is all shown on the plans as well. You use the large fuel clunks. The 40 oz. Dubro comes with this clunk, but you will need one for the 16 oz. b/c it only comes with the small one. As far as a "needing" a UAT? It is not absolutely necessary, but I believe most would recommend it on any turbine aircraft, including myself. A conventional one could do the job though if you were so inclined.

Have fun with your Facet, you'll like it.

George