I want to build a helicopter -- where do I start?
 

I would go for the Raptor. They make one that is partially built with the Thunder Tiger 36 heli engine already installed. They also make a kit, and you'll just buy the engine later. They make a conversion kit for the Raptor that will adapt it to take a 46 or 50 helicopter engine. Mine will do almost anything you ask it to with the Thunder Tiger 36 on it. I've looped and rolled it with no problems. I even went to a heli fly in and one of Team JRs pilots was there, and he did even more with it. He was quite impressed with it since it was the first time he'd flown a Raptor. They also make an Airworlf conversion kit for it aswell.

first heli
 

I would go with a flight simulator...................First things first......You will discover if you want a heli or not........It will save you many $$$$$$$$
Doc