There is no turbocharged or supercharged motor that will fit. The factory VCM II motors were either the type 4 VW engine or the 2.0L 911 "T" engine, none of which were turbo nor could they be easily made turbo or supercharged.

Also, the 911T motor, a 6 cylinder motor, will not exactly "bolt in", as it is a ford vcm 2 dry sump motor so you'll need a separate oil tank, as well as better braking. There are kits available from Pelican Parts to convert a 914/4 into a 914/6, but again, there is nothing turbocharged that will fit the 901 transaxle except VW engines or the aforementioned 2.0L Porsche engine.