Thinking about turbo on my/6 again...
If you’re going to do a draw through setup, use a turbo that was originally designed for it or you’ll constantly be dealing with oil consumption. They have a carbon seal that allows the turbo to be in vacuum and not draw oil. If you’re not interested in power then really any turbo will work that was designed as a draw through. Don’t worry too much about turbo size. Ring gaps in “the middle of the range” (what were they?) will be fine at low boost pressures, up to about 8 or so pounds. This isn’t a rule, but more my experience. If the tune up is good and you use intercooling (can’t with a draw through) you can get away with more boost on tight ring gaps.
My recommendation is do a blow through set up. It opens your choices of turbos up drastically, allows intercooling, and there are plenty of ways to modify a carb or buy a blow through throttle body/carb set up ready for boost.