Oh the D60 takes SD? I didn't realize that. You have a great set up so far and you're going along.
The major reason I got rid of the 2 to 1 was I do a lot of work with highschool youth and well it would suck not having the right lens on to do the job so after a lot of debating, I made the switch and while yes, it's not as pristine it's a great all-purpose lens.
I've never played with a coupling ring, but I've seen quite a bit with them and they look pretty damn good for macro work. I might have to get one after the wedding / house / major life changes all settle down. I do know that I'll be taking the camera on the honey moon, future wife is already starting to play with my D70 so hopefully I can get her as involved with it as I am so I won't feel as bad when I go and get more stuff.
As far as flashes, I have the sb800 but well, honestly, you can get the same results with the 600, I got the 800 for a steal, it was a return to Penn Camera and they didn't have manuals or other stuff with it so they sold it at a reduced cost. Only reason why I have it instead of the 600, and I think the 600 can do master / slave which is amazing for sit down work. I know the 800 can control a 600 but I'm not sure if a 600 can control a 600 or anything else for that matter.