cg125 into xr75

basicly ive got a honda cg125 with loads of low end torque ive been looking at xr75s like my profile pic and the frame and forks are identicle just smaller. i plan on raising the rear getting some nice chunky tyres and raising the mud gaurds. ive seen bbr xr75s but there mono shock and this is twin and has 50cc more and 11horsepower. if you have any info on xrs what tyres how to make it faster or any tips on it they would be greatly aprecated.

regards charlie