If you're adding for 60 minutes (or really anything much past 40), the flavors in the hop description will have vanished. A lot of us just use the highest alpha acid hop we have, both to save money and to have less wort sucked up by the hops. For bittering, you'll want to look at the cohumulone content. The higher a hop is in cohumulone, the harsher the bitterness. If you can't find that number, don't worry; most high alpha hops are low in cohumulone.