Re: Jim Mock Motorsport
Honestly, the first mods you'll do are a better exhaust & extractors, and over many irc/ff chats, the general concesus is that the JMM DEV1 seems to be basically the same deal as pacemakers + whichever exhaust you want (redback is probably a good choice, which is what JMM uses), plus you get some other stuff (XH snorkel, good plugs, good leads??, modified / highflow cat), and a tune up on the dyno (at least good for _some indication of rwkw, even though everyone says his dyno is generous), and for $980, you'll be hard pressed to get all of that anywhere else, either at the same price or more than about $100 cheaper.
You could always go for spare parts, but apart from that, DEV1 seems a nice easy all-in-one solution for the basic performance mods.
As for DEV2 onwards, I think a lot of people have had better luck getting a wade regrind put in, dyno tuned, and have saved a lot of $$$ for exactly the same / better performance.
TQE, SWB, ATPS, Worst of the E-series.. and I wouldn't have it any other way