The VW's I've worked on use a little round chrome fuel pressure regulator.
I've been looking for a boost referenced regulator, but they are all huge. My ATP setup came with a large stewart warner fuel pump and large regulator, I was looking at that Holley or similar Edelbrock pump also.
Space is at a premium, Honda didn't leave many openings.
Google Stormcar fuel pressure regulator, Offenhauser has it at Speedway motors also. I suspect it's the same regulator sold by many re-sellers. You might check VW shops also.
Quick fuel has one with many different sellers on ebay, it's the holley style, I like it because it has two outlets, one can mount a gauge.