The stock America tires seem to be good for 8 - 15 Kmiles, depending on how you ride and road conditions.
Do a search here for whitewalls, the subject has come up a few times. There don't seem to be any the exact size for these bikes. The best fit is a little taller, so you will probably have to make some changes to the front fender mounting. In the photo gallery there is a picture of a set of extending brackets that look and work well. Some have cut the center out of the fender brace, but that doesn't seem like a good idea to me because the fender brace contributes to the rigidity of the forks.
