It looks like a good deal to me. If I do it (and I would probably throw in a Corsa cat back), I will likely go to 21st Century Muscle cars in the Dallas area (Carrolton, if I remember correctly), since the Lingenfelter people in Indiana recommended them, as have other folks. A road trip to Indiana from San Antonio just seems a bit much (still not ruling it out, though, just because they have the most experience and a flawless rep).
When I talked to them, they emailed me saying that the 3 yr warranty didn't apply b/c they weren't doing any internal engine work (What the ....?). So Hennessey's package seems better in this (and perhaps only this) respect (he offers a 1 yr warranty). Also, it's $1995 for the intake, pulley, and tune. The Corsa exhaust is optional (for optional $$$).