I got it.
Now to install the new sensors. I opted to buy Bosch 15738 units. These are the OEM sensors with a DIY connection to use the original connectors. The Bosch connection system is pretty slick so I think it will work.
So main question: does it matter how long the wire leads are? The existing O2 sensor leads are about 6" long. Seems to me that a little extra wire wouldn't do any real harm right? Can just coil up the extra?