There are quite a few alternatives. As far as what most would consider paleo alternatives, the main ones are coconut and almond flour. I use arrowroot even though I am fairly strict, as it works very well to get things near "normal" (wheat flour). It is a must to me for pasta dough, pizza crust, breads and cookies/brownies. A lot of people may argue about if tapioca and arrowroot are really paleo, so as the story goes just use what keeps you healthy and happy.
Also, do you know exactly what Xanthan gum is? Do a quick search and see if it is something you want to use.