As I was reading, I was planning to say that it is your wedding so you should really get to pick it out, but that you should probably at least consider your mother's opinion...but then I read that YOU are paying 100% for the wedding. That changed my mind. If you are paying, then I don't think she gets a say at all. Sorry if that's insensitive. If she was paying and your location choice made it so no one on her side could come, then I think you should try to compromise with her a little. My feeling is that whoever is helping to fund it should be the only people that have a say whatsoever of how that money is spent.
Another thing to consider... Would you have hurt feelings if those relatives really were unable/unwilling to attend that far away? Or would you rather have the wedding in your favorite spot and welcome whoever could make it (and not feel bad about those who didn't want to travel that far)?