If you want to tune and tune right, you should have a WB02. You can also tune for no knock, but I honestly think an EGT guage is one of the more useless and overrated guages available.
Check out the
JAW. Thats what I am going to get, as well as several other members here. If you're half ways competent with a soldering iron, you can get the JAW for $70 if you assemble it, or $115 assembled. The WBO2 sensor is only like $55 or something, plus a few bucks for making the wiring harness and other shit.