Edited to add: The battery is fine, the Charge Wizard did it's job and the battery was fully charged and perfect. I on the other hand am a dork. I forgot that I had hit the "Battery Disconnect" swit...
Since you are always connected to power, other than when traveling, any old 12v battery will be fine. I would probably go with a Costco 12v marine battery, about $80. Maybe your friend can get you a better deal on some other marine battery.