If you decide to do this "fuel module" approach, consider making a round can with a flat and thick (so it stays flat) bottom, and on the very bottom, drill a big hole (1") in the center and cover it with a disk of thin aluminum sheet metal that is smaller than the ID of the can and deburr/sand all the edges. Keep the welds on the outside of the can. Add some stops to keep the disk from being able to move vertically more than say 1/8", but leave lots of free area for fuel to flow by.
The idea is that when you submerge this can into fluid, the disk lifts and the can floods. Lift the can, and it remains full. This would make for a very simple, very slosh tolerant pickup area. That can would be at tank level regardless if you did nothing else.
I wouldn't pour your return fuel into this can; it makes it harder to keep bubbles out of your pickup stream; and if you think about it the level will remain (on average) at the same level as the tank regardless.
This isn't my invention; this is how the OEM ford fuel modules work.
The OEM modules take this one step further and use the return fuel stream to power a jet pump that lifts the fuel from the bottom of the tank (outside the module) into the module. This keeps it full to overflowing all the time; and is even better. I don't know what to recommend for a jet pump design, but if you want a real project, that would be the ultimate.
Reference:
https://delphi.com/shared/pdf/ppd/pwrtrn/series7000.pdf
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