No idea what a pop tune is, but the stock ecu doesn't lend itself to tuning. There is a ton of information here, it just takes some time to sort through it. I suggest you read through the sticky's in the 3rd gen section. Regarding throttle bodies, here's one write up for adding the ITR TB.
Introduction: This is a write-up on how to modify and install an overbore 65mm Integra Type R throttle body on to a B21 Intake manifold. This write-up also includes what parts youll need to do the job the RIGHT way, and what tools youll need to complete the mod. Background info: First things...
www.preludepower.com
There are others that people have used over the years, I just don't remember which ones off the top of my head.