As far as engine goes, all years are the same, with the exception of very minor changes and the style of electrical connectors. If you have a set of or any in frame pipe, it will work with all years. Some pipes require removing the airbox, and other minor mods, but you would have to do that on all years too. Definately remember about the rejet too, you see a lot of questions about rejetting on here, and if you search around youll probably find someone with the exact same setup.
EDIT: I've only ridden dunes once, but when I was out there I had FMFs, and I wasn't going to race anyone with a drag bike, but I had a lot of fun, you'll see alot of guys on here running a trail style ipe like FMF at the dunes, you could definately get away with the DMCs, your not going to have a shit ton of top end, but I had plenty of fun on my FMFs, and pretty much anything beats the stockers.