Get the de-cat and manifold - leave out the bluefin though - put the money towards some mild cams and vernier pulleys - the usual ST170 air snorkel and airbox along with panel filer will work well together - that is the best of the 'bolt on' stuff.

If you are going to get it chipped go for the Datek unit - slightly more flexibleshould you get some more work done at some point - i.e. it can be mapped.