Well, if you want to open a forum then choosing free hosting will be a bad idea cause forum need a lot of space to host and free hosting providers doesn't allow you that much space. And the monthly bandwidth is also limited on free host.
Simply put, "Free things are not for business people" or anyone intending to do business at all. What happens when the owner decides to withdraw the freebie and leaves your site hanging and your clients disappointed. I'd rather pay more and get a better deal than be afraid of the cost and end-up embarrassed. Success
Then go for bigrock... as i have used this and also suggesting others too.. you can see my signature and for more details send me PM..