Garceau, I forgot about these the other day but better late than never - Holley makes "drop in" fuel pump modules now that install where the factory fuel pickup/sender assembly would be so no need to buy a tank. I don't know what car you're working on but they do offer a specific '68-'70 B Body unit with a 255lph pump which works with the basic 4150/650hp unit. You can even re-use your existing hard line. I've replaced a pickup/sender in a driveway, it's not a huge deal. While not a return system, it basically eliminates the need for it.
https://www.holley.com/products/fue...uel_pumps/muscle_car_efi_modules/parts/12-314
Just to provide a real-world example, I ran my Sniper on a basic Edelbrock Performer 383 intake with just a gasket for a year and there were no issues with it. Last fall I installed a 1/2" open wood spacer just to see what would happen - nothing, same exact performance. I left it on because I was too lazy to take it off but again, zero difference. YRMV.
I'm sure you realize this but one of the main advantages of most any EFI system is that the fuel is delivered at 60 psi and does not sit sloshing around in a bowl on top of a hot intake before it's sprayed/atomized into the plenum. Because of this arrangement, the usual problems associated with heat soak are essentially eliminated.
Be aware though, if you choose a Sniper system, the wiring harness they provide absolutely sucks because it's "universal" (read=designed for a small block Camaro). I ended up de-pinning the whole thing and made an entirely new one from scratch to make the wire connections actually work on a big-block B body Mopar. It's mostly assembled with Delphi connectors and terminals so if you plan to "customize" yours, you'll want to figure out what the terminals are and order them ahead of time. Other than that, the rest of install was pretty straightforward.
AndyF makes a Sniper-specific throttle cable bracket. I use one, it works.
http://arengineering.com/products/sniper-throttle-bracket/
He also makes a water neck spacer tapped for the temp sensor Holley uses so if your intake does not have a provision to adapt it or you want to keep your factory temp gauge working, then this setup helps.
http://arengineering.com/products/thermostat-spacer-with-efi-sensor-port/
Lots of stuff out there these days to make the install go smoother.