Two variations of the ProCharger HO Intercooled system and two variations of the Stage II supercharger kit form the whole group of offerings - one of each is a 'system', and one of each is a 'kit'. The systems are fully complete, ready to bolt onto the car. The kits will take some extra work - buyers will have to supply their own fuel system upgrades and ECU tuning.
The HO system includes a self-contained ProCharger P-1SC-1 Supercharger, a large, 3-core air-to-air intercooler, upgraded fuel system and all necessary tubing and brackets. The primary difference between the ProCharger and Stage II systems is the use of shared drive for the ProCharger and dedicated drive for the Stage II unit.
Standard pressures for all of the superchargers is 6psi - when combined with more fuel and a proper tune, that'll boost output by 150hp. Since the SRT8's HEMI starts at 425hp (317kW), adding that extra 150hp takes the total to 575hp (429kW).
Going higher or harder is at the user's discretion, and the need for more fuel and a different tune is why the tuner kits exist. For those not seeking extreme numbers, the out-of-the-box complete systems will be the preferable solution.