I don't know if there is any benefit to drinking alkaline water.. Nor do I really care. I do know that I prefer the taste of alkaline water over bottled water (and drinking or cooking with tap water is simple out of the question in my household).
The Water Store is where I get our alkaline water for $1.50 a gallon. The employees are sweetheart, and always ready to help.
Tip: Closed on Sundays, but if you are getting regular water you can refill 24/7 via the machines outside.