Which O2 sensor for VX???

[hunterhound]

I am placing a 92 VX in an 89 DX. I have most of the things needed, i.e. harness, ecu, etc. but I am looking at o2 sensors for the VX and boy do I get some different prices. I have seen some without connectors for as low as 50 bucks and others that go as high as 400! My question to the forum is how many wires should this sensor have for my installation? I have seen both 4 and 5 wire sensors that claim to fit the 92-95 VX...how can this be? Also, can I get one that makes me use my old connector or do I need one complete with connectors? If anyone can post a link or pm me a link with some good sample sensors that will work and hopefully fall below 100 dollars would be greatly appreciated.