Take a look:
http://www.canyonchasers.net/ then hit the "reviews" link. I like their tire reviews. Might try some of those Conti Sport Attack or Road Attack tires.
Hey, check out this vid of rhinotire... no more flats... watch them drill 4" screws right into the front tire and drive over a board with 100 nails.... no leaks. Wow. http://youtube.com/watch?v=GScWPb8qcng&feature=related