yup, grab a sample from somewhere, sure myprotein or the other main guys offer samples, if not of something you want, send them an e-mail asking them for a sample and giving a reason. Personally I don't have a bad reaction to lactose, but the non isolate whey I feel bunged up and a bit crappy, with the isolate which is "almost" lactose free I'm absolutely fine and have no reaction at all. But grab some samples of other things aswell, myprotein has a pretty long list of various types of protein and lists who they are suitable for, halal, vegetarian, lactose intolerant etc, etc. Read, try samples, go with what you like best. Whey is the best protein you can get, actually quite significantly better than things like soy proteins so while isolate might be expensive, you essentially get more bang for your buck and a much better and more complete protein profile.