your LHS might have them, or most larger online shops have them (tower hobbies almost always has them in stock). As far as the KO propo, from what i've heard from Ko team drivers is that its way to fast for even them (and thats in mod), lol.

in the speedmerchant manual it tells you to line up the front of the servo case with the arm or something like that (sorry i cant tell you specifcally since i dont have the manual and havent done it in a long time). and with the servo saver its phyically impossible pretty much (except if maybe you took a dremel or hammer to the servo) to break servo gears, and messing up the servo saver almost ALWAYS takes place when you remove it or put it on.

it would change the steering geometry because of the height of the ball stud, and thus mess up your ackerman (or at least i am pretty sure thats what it does, also it could rub the chassis since the servo sits on it, and the servo gear sits very close to the ground (since the servo is smaller to begin with).

it may seem like alot of annoying crap right now, however running 12th scale is alot simpler than sedan, just hold in there!