If I'm not mistaken, the first GR shox were the black/silver/lapis BB4's in Fall 2000. The black/orange XT4's were supposed to come out about 2weeks later (but got scrapped, something about the spring plate disconnecting) and white/silver/red R4's were supposed release 2 weeks after the XT4's,but got pushed up since the XT4's didn't come out.
With that said, I thought all 3 were released the same day the BB4's had a GR but only at select stores or Niketowns. That is how some people haveXT4's, since they had a limited release before their GR got scrapped.
The only Shox I'm unsure of is the Olympic BB4's. I don't remember if they came out before the black/silver/lapis BB4's but I am certain thatthe black/silver/lapis BB4's were the first GR (while the XT4's and R4's had a limited release that same day). I think the blk/sil/lap came outfirst since the Syndey Olympics took place in Oct. but I'm not 100% sure.