I have the opposite problem with my cat - his hair's all falling out, but it's of his own doing. He's got all sorts of weird skin problems, though, which we're trying to sort out.
I do have a furminator for the dog, and it's brilliant (he sheds pretty much year-round). I don't know how well it would work on a cat, though, as it's basically a shedding blade - a bunch of sharp points with spaces in between to catch the hair. The dog's not really keen on being brushed (though he puts up with us because he loves us), I think the cat would really hate us if we tried it on him.
Hope you find something that works!