I bought both the Y and the Z from them as well. As you can see from the link, my mill is different to yours so I couldn't use the supplied Y or Z axis extensions because of the tread size, but you will be fine being a Bridgeport clone. I chose to make my own spacers to bolt the power feeds onto the machine, as the holes didn't quite work out, and mine being a different machine and mounts, but could have used them if I really needed to.
Mine have been on for about 3 years with no problems.
I had something fall between the knee and the saddle that I didn't see one time, and the power feed stalled, and then wouldn't work. After scratching my head and thinking I'd blown it up, it only needed the reset button pushed, so there pretty robust.
You will get everything you need for the axis you buy in the kit, with a few extra bits and screws as well. You will get all the shims, keys, track for the limit switch, etc.
The price for these power feeds over here are $750 eachAU. I bought the Y and Z from over their for $630AU shipped, and that was when our dollar was low.
This is the mill I fitted them to.
https://www.machineryhouse.com.au/Products?stockCode=M161D
Davo