I've found a forum niche that I think will do very well and now I am working on finding the perfect domain name to go with it. I'm looking for suggestions of whether it should be something as follows, let's just say the niche is Furby toys as an example:

furbyforum.com
furbyforums.com
furbytalk.com
furbygroups.com
furbyhub.com

I only want to buy one domain and it will be to discuss the niche item and maybe review products.