I would personally only fit denso o² sensors, nothing less.
Regarding the socket, i prefer a good quality 22mm spanner. However, a special socket is good to have. on my last trial, my special socket slipped, the spanner however worked.

 

Thanks guys. Just got the car back from my mechanic. A few days a go a new code popped up – P1349, "VVT System Malfunction." From threads here & other googling I determined it was probably the oil control valve. I decided to bring the car to my mechanic. He confirmed my diagnosis and replaced it, but I figured what the hey and had him do the O2 sensor too. In retrospect I could have probably done all this myself but it would have been a bit of a risk. My wife actually pushed me to take it to our mechanic who is excellent and honest. One thing you couldn't call him is "inexpensive", lol. He did go the extra mile and made sure the codes all cleared & stay cleared, and got an inspection sticker for my car – if you're from New York State you know that's not always easy with cars that throw those cat-related codes (not without replacing the cats anyway).

Thanks again for everyone's input in this thread. I'm keeping my O2 sensor socket, hey ya never know!

[edit] PS - for the sensor, Denso - my mechanic says that's the only brand he uses.