Whipple used to make a supercharger kit for the 4.2L I6, but I am pretty sure it was discontinued due to lack of sales and interest.
The hotter version is the TrailBlazer SS. It is available in 2WD or AWD (yes, AWD, not 4WD) with a variant of the LS2 Corvette engine. V8, 6.0L, = ~12mpg.