Orion 2ktc. The most important upgrade is the rear suspension hangers. Also go to the 1st page of this thread and all the info u need is right there. Carbon fiber shock towers are just bling. Money would be better spent on tires and track time. You will love this car its definitly quality components, fit and finish. As far as building it. Just take your time and pay attention to everything inthe manual and to the fit and free movement of all assembled parts. There is nothing that you should need to jam together it all fits together nice and smooth like every other kyosho kit. Any questions feel free to pm me or ask here theres always someone willing to help out