My car isn't race spec, yet, I'm using the standard ERST fuel tank, as all the UK spec BTTC, rally and Group A cars did with an external swirl pot. The European cars ran an ATL 80l bag tank, but after speaking to a German chap who builds them he does away with these ATL tanks and fits standard items like the UK cars, but I digress.
As you said though, I wanted to return the fuel to the tank to prevent over heating that's why I wanted to know if I needed twin lift pumps to keep the pot full. I think for peice of mind, I'll run a pair of Facet red tops and see how I get on. Not sure why I'm bothered about how noisy they are when I have a straight cut box and a stripped interior
So you have an RS Turbo tank, with presumably an RS Turbo efi pump already there which will flow plenty. Why buy a different pump as a lift pump when you already have one ?
Will a Facet flow more than the Bosch pump ?
What is the main engine pump you intend to use ?