You could try:
http://www.trueprotein.com/Default.aspx
I bought one of the 25-lb recession whey recently. I know, I'm insane. I got some flavour packs to mix in, but on the plus side the powder is unflavoured and unsweetened. I've actually used some of it in baking, and it worked quite well. And no, you don't have to buy 25-lbs
There's quite a long discussion here, in another area, about the types/flavours and some of the people posting there might be able to answer more questions.
Trueprotein