Try Riversports Outfitters on Sutherland Avenue in Knoxville. They rent whitewater boats. I think the rental fee is something like $35 and they include sprayskirt. I'm not sure if they include paddle and helmet but they might. We just have never needed it so didn't ask.

2918 Sutherland Avenue
Knoxville, TN 37919
Phone: (865) 523-0066
Fax: (865) 525-6921

http://www.riversportsoutfitters.com/t-locations.aspx