I bought one from pep-boys for my Stoichiometry Guage. First i got the generic one, with 1 wire (sender) but then decided since i had headers it might not get hot enough so i returned it and bought a 3 wire-bosch (sender, positive, ground) the 3 and 4 wire O2 sensors are HEATED which is very important if your O2 sensor isnt getting hot enough. Trust me, get a heated O2 sensor. all of them have 3-4 wires. 1 is always sender, 2 are positive and negative, and on 4 wire O2 sensors im not sure what the 4th one is for.

Yes they all do the same thing exactly, buy the cheapest, heated O2 sensor you can find. works great!