I basically use a Bosch CIS-spec fuel system (as I started by swapping CIS in)
914: -044 Bosch pump, 1.5 L swirl tank (~vertical on firewall, made from 3" SS tube) kept full with a 20 year old carter clacker with a Bugpack sticker
Squareback w/T4: moved the whole setup from the 914 over, with the sump tank off a VW Fox or ~86 Cabriolet mounted on the back of the beam.
(now running MS3/MS3X on a v2 mainboard, also works just fine on a v1.01)
I ran 3/8" feed and 5/16" return lines, using steel brake line. Massive overkill. Works fine and is cheap and easily available at any FLAPS.
On my cabriolet, same setup with tiny VDO in tank feeder, as it
IS an 86 cabriolet with CIS (still)
~any CIS setup will have a big honking (and cheap) 10 micron fuel filter on the pressure side.
I run a large std fuel filter (FRAM off the shelf unit)
after the clacker feed pump. It can eat garbage just fine.
If you have trash in your tank, save yourself a headache and perhaps expensive parts, clean and coat your tank.
If you choose to use a roller cell pump, use a feeder and sump tank.
The -044 is rated for flow at ~90 PSI (not at zero backpressure like a Walbro) so it's
theoretically a 600+ HP capable fuel system. (I am not running boost yet, but I doubt I'll ever need to upgrade my fuel system)
