I'd say go for the SAS but really, really think about changing to the 4.3 combo... In stock form the horsepower numbers are comparable between the 2.5l and the 4.3/700r4 combo but the 4.3 combo ways a lot more so the overall performance would be worse. Of course there are a lot of go-fast goodies for the 4.3 and the torque numbers are higher. So, with $$$ the 4.3 could be good.
Good luck and let us know how it goes!
-Eric