who can i send my rifle stock too to have texture added and have it painted

+1 on all of the above!

Additionally, depending on what sort of "texturing" you are talking about, that may be something that you want to DIY before painting to ensure that it is exactly what you want. I have seen some people have texture added to the grip and fore-ends of their rifle stocks only to have to sand it down or otherwise modify it because it was too aggressive or not aggressive enough. Otherwise, if you know exactly what you want, then it shouldn't be too big a deal to have someone in the custom coatings business to do the texturing for you.