I would say that if reliability is your number one priority then a stock Zenoah G45 or G62 is the best choice. With the stock magneto you will never have to worry about a battery or electronic ignition failures which do not happen that often but can happen. Down side is extra weight and more difficult to start but Zenoahs will run forever. As far as tuning, I've found once you get them set right you'll probably never tweak them again unless you start changing props or see major climate change.