Milk kefir is very valuable in the fight against candida. I used cow milk for my kefir at first, and later switched to goat milk. Goat milk is much easier to digest (different type of casein), especially for candida sufferers. But if you can't get goat milk, don't let that stop you and do cow milk kefir. After the fermentation (48hours for me), lactose is very much reduced and the proteins are also pre-digested by the grains.
I did a lot of water kefir too, but I would always get a quite sugary drink even after long fermentation time, and I think it's definitly not a good thing for candida issues. But it did wonders for my parasite
Never tried kombucha, I'm a kefir fan.