I just got mine done a month ago. I believe it is 60wt oil that you need to use. I am not 100% on the amount that you need though. My mechanic just called Buell to find out how much and then he added an extra ounce so it would make the front end a little stiffer.
When I put my new fork seals in and change the oil a month ago I could feel a good change in the suspension. It is much better now and it only had 7000 miles on it when I got it.