My favorite two are ATI & PTC. I used to run a PTC 8" 5000 nitrous convertor in one of my old Pro street 69 Charger for 5-6 year on the street until I sold the car. Totally street friendly until you mashed the throttle & then it would do what it needed to do.

I currently have another PTC 9.5" 3800 convertor in my street driven cruiser 70' Charger with well over 30,000 street miles on it & is about 10 years old now without any issues.

I also have another PTC 9.5" 5400 Nitrous convertor in my 70' Hemi street/strip 70' Challenger. No complaints from PTC from me.

ATI is usually more expensive than PTC but so many of my buddies are always returning them back & forth between ATI & Ultimate Convertors to adjust the stall up or down several hundred RPMs to get them right.