Wide band simplicity?

I have read quite a bit and have done a search for wide band. Everyone I see talks about sensors and tons of things that basically don't work on the street. My question is.

Is there a wide band 02 sensor that simply replaces the factory ones? If so how much? do i need 2 or just one of them?

I'm looking for the most cost effective way to get a wide band to tune my car? and maybe a friends car?

Thanks!