You can get the Furminator at most pet stores. I know PetSmart has them (that's where I got mine), and probably PetCo. You can also get them online, at Amazon, or eBay. I guess it would just depend on how quickly you want to receive it.
I also have a Zoom Groom, which I find nice for a quick brush now and then. I find the Furminator works really well, but it's takes some time to use; my bunnies don't like to be brushed, so that's sort of an ordeal for me. The Zoom Groom looks like it wouldn't do much of anything, but works well for me. I can get a few brushes in while I'm giving treats; every little bit helps. The ZG is also less expensive.
PetSmart has a good return policy, so you could try out some different brushes there. Make sure you keep the receipts and packaging, and if one doesn't work, just clean it and return it within 30 days. (These brushes are too expensive to be stuck with one you don't like!)
Overall, I do find that I can get more fur out just by petting with damp hands, but I know others swear by their Furminators and Zoom Grooms.