Ive got a Fill Rite on my drag tank. Its at least 12 years old and works great. I dont use it much any more though, just for filling the pickup. I put a filter base from NAPA along with a spin on filter from them as well. I like the spin-on filter, cause DOT cant see what color the fuel is!
I think mine was rated at 15gpm, but I know it was never that fast. Anything you add to the line is gonna slow the flow down.
You guys have had good luck with those GPI's! I ran one for one summer and it burned up on me. I thought they were compleate junk!