Never been to Zok's as it is not near me, but would like to. I was at a homebrew competition in Newtown and Paul won a ton of medals.
I go to Maltose Express near me and they are very helpful and knowledgable. They have great prices on ingredients. Sometimes there supplies are a little pricey though. I have to get somethings online, because I just can't afford everything there, but I buy what I can to support them. They are always busy, so I don't think they are going anywhere soon!