Oh autocorrect. Yea, typically people go for the cheapest alpha acids they can buy (I use bravo, myself), however certain hops have lots of cohumulone which is largely responsible (among other things) for a harsh bitterness. You want to make sure your bittering hops don't harsh your beer too much unless that's what you're going for. Also, there are certain times when using a lot of hops is desired- using a ton of low alpha hops early in the boil can give you a nice lush sort of tannic quality to a historic style porter or stout. There are lots of exceptions, but in general, yea, it doesn't much matter what bittering hops you use.