Why would you spend that kind of money for that! Wow… $650 is way too much.
You can go and buy a normal chest frezer and an seperate thermostat controller for it and turn a chest freezer into a keg box if you want for way less than that.
Do a seach for “chest freezer keg” and you’ll turn up a ton of links. You can get a 7.0 cuft. unit, an thermostat controller, and modify the top (so you can use it as a chest freezer still if you want) and be around $300. Now.. it won’t fit under your bar and if that’s a requirement then this doesn’t help.
If you have the space, do the above and build your back bar around the chest freezer so you can slide the freezer out from underneath the back bar to load and unload it and have storage.