I think EGT is something of a novelty. Good info...for sure. But if you are doing a WOT pull on the street the last thing you should be doing is staring at your EGT gauge. At least, thats my opinion. The essentials are boost and oil pressure. After that, a wideband is really nice to have. Suggest the AEM unit, and get the matching electric boost gauge (not the tru-boost but the boost-only variant). Slap those puppies on your steering column and put an oil pressure out of the way for glance-over-just-to-check purposes.
Also you MUST run an electrical oil pressure. A mechanical OP would have you running an oil line into the cabin which I highly disagree with!
Ninja edit - when installing the OP sender unit do NOT use brass fittings!! THEY WILL FATIGUE AND BREAK! ony up the cash and order stainless steel fittings. IIRC you need a 1/4" NPT nipple and tee for the OP low switch location.