The headers are the only reason why I would stay away from Superchips. Longtubes, whether you run them with or without cats, are going to be prone to throwing an occasional check engine light. Superchips does not give you the ability to tune for the longtubes, so you will be stuck with the light, and the air/fuel is going to be a bit on the lean side.
Without headers, you would be fine with Superchips. A good custom tune will always get you more power than a canned Superchips tune, but it is a good unit for anyone that wants to stick to basic canned tuning.