For a little VW the Cat Filter wouldn't be more restrictive, the applications that CAT uses them are as the only filter or as a secondary filter are huge, think D9 and D10, in other words, giant thirsty engines like the 3208 / 3408. The CAT filters are popular with the Duramaxx guys also, so a 1.6L or 1.9L VW with a VE is no match.

That being said, there is a second Part# 1R-0749, that also fits the PermaCool Heads and is massive, I doubt you'd be able to find the space to fit one in the engine compartment of a VW. I used to use one as the final filter on my VegOil Tank. I built my setup to filter in steps as I filled the car, I had a 100 micron stainless steel screen on intake pipe, 30 micron filter, then a 10 micron GoldenRod, and finally the 2 micron CAT 1R-0749, it is giant. The whole setup flowed well enough to use with the rotary pump to do Vegoil fill ups in 8 minutes or so with ambient (75F) Vegoil.
My 03 TDI didn't have a lift pump, it never had issue flowing enough fuel through the CAT filter even with 100% Vegoil on a Cold (for Florida, 50F) morning.

There is a PermaCool filter sitting on top of the tank, you can get an idea of the size in relation to the 1R-0750 filter.
There is a PDF from CAT that has allot of details about the HE filters and their construction, here. They are also designed so that very cold gelled fuel still flows. As for the bottom drain, I read a second hand "unofficial" post on the GM Diesel forums a couple of years ago that according to a CAT "expert" certain filters have no drains by design. The reason was because in some applications, these filters are the secondary and a higher micron primary filter has a drain and it was expected most water would end up there and also that based on the design of the filter and the change interval, it was expected that not allot of water would collect if the filter was the primary.
If you want a drain, Caterpillar Primary Filter/Water Separator Part # 175-2949 is for you, it also fits the PermaCool heads, however, it only filters to 10 microns.

If you want to go nuts, you could do as CAT does in some applications and have two filters, a 175-2949 as a primary and a 1R-0750 as a secondary.
I posted a
detailed thread to the GM-Diesel Forum a while back, when I had the 79 Chevy with the Olds 5.7L Diesel 350 in it. I even made up a cross reference for other brands. Lots of info.