Tube Help Needed

Hello BTers, I need some help, advice. I recenlty got at P2SL and am finally use to it enough to take it on long rides (First Road Bike I ever owned). I am wondering if anyone knows of any good inner tubes i can get to bring along with me on my longer rides in case I get a flat. I have the Vittoria Diamante Pro Lite Tires along with the Velomax Vista wheels that came stock. Anyone have a P2SL or have any recomondations of a good back up tube to bring along on long rides? Thanks for reading my post.