Connecting metal lines to the fuel tanks is not difficult.
Here is my presentation on installing in-tank fuel pumps. It shows how to cut the swedged end from the fuel pickup lines and the use of brass compression fittings to connect the metal lines to the cut ends of the pickup tubes..
Even if you are not putting in-tank fuel pumps into the tanks this is a good way to eliminate the rubber hoses. I installed metal lines all the way from the fuel tanks to the throttle body (TBI) or carb if that is what you are using.

http://www.gmcmi.com/wp-content/uploads/2013/02/In_tank_Fuel_Pump_Presentation.pdf


For the rubber vent lines I installed steel lines over the top of the fuel tanks and down to the sides of them. This would allow me to monitor the rubber vent lines and easily replace them if needed without dropping the tanks.

Contact me if you need more information of suggestions.

Emery Stora
77 Kingsley
Frederick, CO