There has been some chatter recently (and a TSB from VW sometime ago, see below) about using a higher capacity oil filter on TDI EV and Vanagon conversions. All of these filters will fit the AHU/1Z TDI engine. The stock AHU/1Z one is on the far L, the A1 Rabbit one is in the middle and is a fraction taller and maybe 1cm wider, and the 93-95 2.5L Eurovan one is on the far R, noticeably taller and about as wide as the A1 filter.
If you want to have greater oil capacity and have the space then the early EV oil filter is the way to go. If you don't have much space lengthwise but want to hedge your capacity up a bit, the Rabbit diesel (78-84) is a suitable choice. And if you're a stockophile like myself, then you might just hang your oil filter hat on the good ole AHU/1Z filter (Mann W840/2).
For more info on the Technical Service Bulletin issued by VW, google
VW/Audi TSB #04-01 Group 17.