I have a turbo on my Phazer and if I was doing a new Phazer I would go for the supercharger.
If you boost a Phazer the problem is the clutching. I had quite a boost lag that I was told was common with turbo Phazer but it seemed a clutch issue causing the lag to me. I solved that isssue by putting Nytro weights in the primary and putting a secondary off of a Mountain Max on the secondary so I could get a stiff enough spring. The Mountain Max secondary will fit if you either drill out some of the splines on the secondary or do like I did and lengthen the slots on the secondary shaft. Oh, one other thing is you will need to go to hardware store for longer bolt and cut a spacer to fit.
The "reverse roller" secondary from a Mountain Max really is a huge improvement. BTW if you can find mid 90s vmax I am told they fit Phazer without modifications.