Where did you find those Paris Dakar rims? I had a set of those in the original version (sold with a set of green matching hubs on a card 126mm OLD). I've still got the back rim somewhere and the hubs are still going strong of course!
However, if those are the original spec Paris Dakar rims (which were pretty wide), they won't fit in an RC100 with Maguras. They're simply too wide. You could get someone to make you up some new brake mounts to move the calipers out, but otherwise you'll have to track down some skinnier hoops.