kastle: The cooler EGTs at the collector would be expected - the uninsulated Borlas can shed a lot of heat by that point when compared to the insulated stockers. Hopefully you aren't using that point as a tuning reference, since your temps at your cylinder head are probably just as high. (edit: Which collector are you referring to? The first collector on the 2.2 is way back under the tranny, but I realize that this isn't true for the 2.5. I was assuming too much.)
eaalto: I thought (but haven't confirmed) that o2 sensors were a standard size. When I installed my TEC-2 I got a bung from an exhaust shop and they just handed me one. It worked perfectly. Then again, the TEC uses GM sensors, so that bit of information is probably useless.
Jeff