My wife has been bugging the hell out of me to build a Keezer..... I sure do love my wife!

So There is one catch, she is a cherry cola drinker and wants to make her own cherry cola and have it ready on tap. Now I have read horror stories of people trying to do this. Am I missing something here or is it just not a wise idea to do? We could bottle it I suppose.
Take care!
Ray