I installed a summit UEGO in my build. It's exactly the AEM unit rebranded with a different faceplate.

I've only had it in and used it for cam break in and 4 different 10-15 minute test drives, but it seems to be working correctly and very responsive to show changes as it relates to tuning. (So far set idle mixture, checked off-idle AFR, cruise AFR)

Price is right too, less than $200