If you are willing to go down to atlanta, check out audio alternative.
They have all the Grados, and when I went down there, they put me in a listening room on my own with an NAD CD player, an amp, and a hanger of all the Grado models. The closed the door and said come out whenever you want. It was great. I went there thinking about getting 325i's, i ended up getting RS-2s. Great service.