Another place that makes tanks is Hot Rod City Garage there in California. I got an all aluminum tank from them for my EFI build. It's a really nice looking piece will pump and all. I think it was $800 for the tank, pump, and a new sender shipped to me in the midwest. You can get some custom work done on the tank as well like deeper sumps for more capacity and whatnot, just have to call and chat with them. You'd probably save $60 or so if you could pick it up yourself instead of shipping it too.
I think most EFI computers will tell you to wire straight to the battery, you need a real steady feed line for it to calculate injector timing values. I know that was one problem my friend at work had. He fought and fought with it when he first installed it and once he changed the wiring it started working for him.