[sweetpea]

1. I like JR8411's. Can't help you out with the Hitecs but others will chime in here.

2. 42% products are supposed to be decent. I've read a few instances of the optic kill failing here on FG, do a search and research up on it, it may be nothing. I've always used either Electro Dynamic or Smart-Fly optic kills though with zero problems. But you can't go wrong with any of the 3 vs not having one. The ability to kill the engine without a servo is good for safety.

3. Personally I'd go twin. No difference in tuning other than the # of turns for High and Low needle might be different. But on a single or twin there is the same 2 needles. Twins tend to shake less and put out more power in a stock setup but cost a little more. As far as exhaust.......that depends on where you fly. If you ever think you'll fly at a noise sensitive field (which is likely in the SW) then I'd put some cans on it eventually. You can sometimes find used ones pretty cheap