[Sugarphreak]

I think you can get away from the E-manage especially considering it is just Naturally Aspirated; but as a counter point if you are going all out on headers, cat removal, full exhuast, air intake & manifold, most people that check are running a touch leaner than they should be. Something less expensive like an Apexi-Neo can be used to correct it.

I would say once you have your setup finished it never hurts to book some time on the dyno and have them throw on a wideband. It gives you an idea of exactly where you stand as far as power goes as well as an indication if you need to tweak anything at all before you start spending money on tuning gear.