Just to follow-up, I believe I am going to move forward with this gauge:
$320.98 - AEM WIDEBAND AIR/FUEL & BOOST FAILSAFE GAUGE | (30-4900)
I am talking with AEM and they might be able to modify it to supply a Narrowband Emulator output as well, since that's what my piggyback will use to control the system while keeping it in closed loop. This way I could use a single O2 sensor instead of having two bungs right next to eachother, doing the same job.