I'm helping my friend (He's 15) look for a different sled. His ski-doo has leaf-springs and should've died long ago. It tops out at 50mph and can't handle any bumps. This causes problems because he always wants to ride with me. I need to confince him to get independent front suspension. He doesn't have much of a budget. It also needs to go at 65-70mph. I'm thinking a mid to last 80's Indy trail, maybe. Other ideas?