I just oredered a Meta42 Headphone Amp. You can have one made for you by any number of people on the Head-Fi.com site. Some of the better known members that have a very good reputation for making these are Tangent and JMT. Tangent is making mine. Depending on what you are looking for, they will run anywhere from $100 to $300.
I have Sennheiser HD600s (very similar to your 580s), and I don't have my amp yet, but from what I have heard they are a good match.
Later, Snow