Does anyone sell Webkinz Party supplies?

My little sister has a birthday coming up and wants a webkinz party at the park. So I said yes, but have NO IDEA if they even sell webkinz party stuff. Do they? Like, plates, cups, banners, exedera. And if they do, where? I'm also wondering if anyone knows how to set up webkinz games. Anyone who can help??? I've looked at tons of websites, but all of them just show how to make cookies and stuff and what to put in goodie bags. HELP!!!!!