are you wantin to run carbs or efi? if you wanna run carbs stay far away from a 600rr motor..it takes a lot of custom parts to do it. you can do it with an f4i easier, but in the end its not as easy to adjust...so its a tradeoff. i would just buy a carbed motor unless you wanna try to fab up some sort of fucked up air box or like stan, know what everything does and how to bypass it. also, this project is gonna take a lot more than you think. cutting, welding, bending and all that take alot of time and i wouldnt trust anyone but myself to work on mine. i would NEVER not be there...simple as that. if you trust them thats fine but do these people have the first clue as to how these things work? if not i would consider other plans...