OK since you asked about the ARF, here is a recipe for success. Use your Saito 100, make it a taildragger with light weight gear, install a 16oz Dubro fuel tank (yes it fits), install 2 Hitec 225 servos in the tail (yes tail) which eliminates the rod flex, leave the elevator alone (it is fine), enlarge the rudder if you want by about 25% (more like a Cap or Extra style (look at the H9 Advance 40). Now don't worry about the cg, it should fall about 1/2" to 3/4" past the rear part of the cg range (trust me on this). Now how do I know this? Well I have one setup basically just like this. Mine has a ST .90 2c, servos in the tail, 16oz tank and balances 1" behind the rear cg mark. It flies GREAT!!!!! These are very tolerant of cg location. I have a NIB T60 ARf yet to finish with a .91 4c, the one I'm flying now was crashed into the back of my wife's Pathfinder! The damage was minimal (plane and truck) and the owner gave it to me instead of fixing it. I did the above mods and am flying the daylights out of it. BTW, it will knife edge as long as you want and I have not done the rudder yet!