parts of an nitro r/c car?

i am planning to make a nitro fueled rc car or a monster truck. i want to know the differences between them. so that i can decide which is easier. also, i want to know the main parts of them…
i m going to build them from scratch.. i m planning to do all of it on my own.. -the chassis, radio control, etc..

I don't know your level of expertise on this hobby so sorry if I sound to vague. The difficulty in making either won't be much IMO, i wouldn't know because I have never attempted to make one. No matter which one you make you will still need a remote, receiver, two servos, an engine, a transmission/differential, some sort of drive-train, steering, suspension, and tires/rims. The major difference between the two would be the tire size, suspension, and chassis. Are you trying to build a kit? or from scratch?