RRS Supercharger upgrade 4.2L?

[DiscoChic]

I completed an upper pulley replacement and ECU remapping on my RRS 4.2L a year ago; Its working pretty okay but only on low revs. I have been looking for a possible replacement of the supercharger with a Twin Vortex, however I understand the Twin Screw is much more efficient on power consumtion and boost.

I would appreciate help on this. Besides Arden upgrade, the last I checked Eurotoys were still working on a Twin Screw for a 4.2L.