You could also look at the RS1i's if You want to get Grado's, and get a better sounding Headphone amp. It depend's on how long are You going to listen to the phone's because Grado's are very uncomfartable on long listening session's. What kind of set up You have, what do You mainly listen to and how much are You willing to spend. Then there is the burn in process for everything to sound much better.
If You're going to be running off the computer your better off with a DAC/AMP, look under the Head Gear section and narrow You're result's there, check rating's, review's and look into price's, probably in the range of the RA1, higher or lower to see what's going to best suit You're needs. Take You're time it's not a race and enjoy!