Force users new site name to be the same as his user name?

I installed the plugin that let’s me limit each user to one site. Now I’d like to set it so that the user has no choice but for his site to be names the same as his user name. Is there a setting, plugin, or other method to achieve this? I’ve so far been unable to find anything.

I found TuKod Multisite Site Names, but that doesn’t do it. It allows you to give users the option to name their site with a username, but that isn’t good, as they can fill in ANY user name, or still just use any random name they like.

Not sure if it’s important, but I’m also using BuddyPress on my network and main site.

Thanks