I used one of these.The tanks they are available now below 100$, add to that the lines, fittings and filters (don't forget filters before and after the external pump/s) you are looking at least $500+ and you already have the pumps. I designed and made my own surge tank, I couldn't see paying 500-600 for one back when. Now they are all over. eBay and Google will show you stuff, just search for "Fuel Surge Tank".
Mine had to feed in corners, so each pump picks up from the side and I had to have enough fuel in there to feed 800 plus HP.
Like they said starvation will KILL your engine.
PS: The overflow from the tank feeds back into the fuel tank and the return feeds back into the surge tank like the others.
I had the top welded shut and a few more bungs welded on but it has worked great.