You should stick with the stock tranny gears and the UE idler. you will blow the lightweight gears up under dual power. the y adapter will allow you to plug both controllers into the throttle channel on your receiver. You can get them at your local hobby shop (not sure what is local for you, but Ultimate Hobbies will definately have it, although they are about 45 minutes or so from Corona).
It looks like UE is out of their hardened steel idler kit.
I have 3 hobby stores by me to choose from, Hobby Town USA is 5 miles, Hobby People is 11 miles and Ultimate Hobbies is 19 miles. Do they come with the deans plugs on them allready or do I put them on?
They don't use deans plugs - they have servo leads, as they need to plug into the receiver. basically, you plug bothe controllers into the adapter and plug the adapter into the receiver where the controller would plug in.
I live about 8 miles from Ultimate Hobbies.
I brought my Super G-Maxx in there before because one of the guys working there wanted me to bring it in to show him.
Yup definately you will need the Y-Harness for the two receivers you are using for your dual Feigao project.
I would recommend you power each ESC with it's own battery but you can power two with one if you really want, but the run time will suffer.