Cat 5e has a range of over 300 feet with a capacity of 1,000 Mbps and is reasonably priced. Cat 6 has about the same range but with a capacity of 10,000 Mbps. So you'd probably be fine with 5e but if you get a good price on 6 it would be more "future proof" (I hate that term but you know what I mean ;) )
Honestly I'd get the 5e unless you think you'll be needing 1,000+ Mbps transfer speeds locally (file transfers from computer to computer, computer to local server, phone to computer, etc.) because ISPs probably won't be offering internet speeds of more than 1,000 Mbps service anytime soon.
http://www.bestbuy.com/site/tripp-lite-100-n001-series-rj-45-snagless-molded-cat-5e-patch-cable-black/4541432.p?skuId=4541432