My Sig Sundancer came with a tank which I chose not to use, I prefer the 24 oz tank from Great Planes. The pickup from the clunk goes to the carb nipple (via a DuBro fueler, in my case). The vent is at the top of the tank and you simply need to run some tubing from there to outside the plane. I put mine just behind the firewall out the bottom. When I fill the tank, I can tell it is full because gas runs out the vent. But since the vent is on top of the tank, spillage is minimal. If the plane is inverted and the vent is on the bottom, then the tubing exit will always be higher than the tank itself.

I don't have a US engine but I assume it has a choke and no pressure line is necessary to get fuel to the carb.

Larry