Jackson Racing is an older company that used the Eaton series, model M62 (on itr anyway). They had an inefficient design which resulted in very hot IAT at boosts above around 9psi, and thus high power ouptut was limited potential and required a heat exchanger setup. Eaton have just released the TVS series of chargers which have a roots style setup, but is referred to as a Twin Screw setup due to the evolvement in design. This is much more efficient, however still not as efficient as a centrifugal system (Rotrex, Vortech etc). The fact that a centrifugal needs revs to boost (still no lag, just a more linear power delivery) means that the Eaton series chargers will be more responsive at low rpm as full boost is achieved a basically idle -- The centrifugal setups will have close to full boost by 3500rpm and have the capacity to build up to 25 psi efficiently with an intercooler setup.

I am assessing my options currently and looking to go with rotrex -- Expensive excercise, expect around $10-$12k + ECU.