I would say that it kinda depends on what everybody else in the group is riding. What I mean by this is that if every body has a sled with a track that's at least a 151", you'll want to put a similar track on it. But if everybody has later model sleds like the 2000 700 all you should have to do is upgrade to a 136x2 track or even if you wanted go with a 144.. But the key difference between the SKS and the RMK is the 2" paddle track vs the 1.25" paddle track, which makes a big difference believe it or not. (There might be more, but as far as I'm aware of that's the only big difference) I really have no idea what you should do to the sled as far as clutching and jetting, but I'm assuming it will need clutched and jetted.. My advise would be to put it to SLP's specs with the single pipe mod, which will be a good area to start at as far as jetting and clutching, however I could be wrong.. More then my input would be helpful lol. As far as performance goes again, if everybody is riding newer sleds you might actually want to put an SLP pipe on it, their Air horn kit, and maybe even gear it a little differently. But as I said above i can't be sure without knowing what your group rides, and I'm no where near the expert on clutching and jetting that I wish I was.
Hope this helps.