I just took the plunge...
primarily people like to use muslin cloth or seamless paper
both have their positives and negatives...
muslin is easier to store, you get more texture with your backgrounds but is completely awful to iron out all the wrinkles...
also good quality muslin, that does not let light bleed through is going to cost you...
of course their is the DIY route, somewhere in the forums there is a link
seamless paper can rip...if your going for the 107 inch better be able to have a place to store it, it be WICKED long
it gives you nice streamline backgrounds, but has a lesser shelf life than muslin but is cheaper...
final verdict out of all that disorganized rant...
get some black and white or grey muslin and seamless paper to start out...see what works for you better...