See TDR #37 for airflow information. Within the range of best efficiency, the HX 35 flows 600 cfm, the HX40 700, the H2E 750 and the HX55 850. All will flow more if you accept lower efficiency ratings.
I don't know how much fuel my engine uses, since it is determined by the pump and by the injectors. A pump that can flow 1000 cc/1000 strokes won't help if the injectors can only pass 200 during the time period the fuel is available.
Lots of folks use Pius turbos. For example the Erb Brothers in California use 3 or 4 of them on each of their pulling tractors. Bell is a small shop and he doesn't advertise to get bulk sales. His custom work is just that and takes a lot of effort to optimize for the engine.