You will only need to drink 2 - 4 ounces of kefir a day. If it hurts you tummy when you drink it, you may be drinking too much for you.
Sleepless, being as how you found it so sour, did you buy the unsweetened? You can add some stevia to it to sweeten it a bit. Stevia is generally considered safe even for those who have issues with candida.
Waverunner, the taste is closer to yogurt, only with a little more twang possibly.
Tickle, I ran across a site that has raw milk producers listed - look closely and you will see even raw goat milk for some areas. But please, buyer beware!!! If the facility doesn't strike you as being clean, don't buy it!!! Ask tons of questions of them also, like how much do you sell?, has there ever been any health issues reported? and other questions like that. If in doubt, don't buy from that person!
Here's the link:
www.realmilk.com/where01.html