Since you said you do have a Whole Foods, I prefer their 365 brand soy milk in the plain flavor over any. It is cheaper and I think much more yummy than Silk and other brands. But, I do like silk. My least favorite is the Giant Eagle brand. It tastes old to me.
And for my own knowledge- Lactaid isn't vegan, right? I think I remember checking it before, but I'm not sure.