After riding to work a lot during my internship/REU/whatever thing, I'm back home and want to keep riding anywhere I can. I have an old hybrid mountain/road bike which I really like, but the tires are getting old, especially the back one is getting frayed and I'm getting a bumpy ride for some reason. They are 700x35c tires, and I'm having trouble finding them online. I found plenty of 700x32c, but I don't know if that would be good enough. I think 3mm isn't that much, but then again I don't want to wipe out while going down hill on a busy street. While we're at it, what size tube should I get? Same as the tire, or slightly smaller?