I have no recommendations for your unit, but a few bits of information.
Scale is caused by dissolved minerals that cannot be filtered out 'cause they are not particles. (Unless you go to reverse osmosis and then there are other problems re: coffee.)
If you water is soft already, then it is not going to scale, so a carbon filter to clean and polish the water is likely all you would need.
A counter-top refrigerator would probably be expensive.
Check with Bombora, our friendly sponsor and water treatment expert.