I also recommend against the "screw lock" and similar connectors. The little plastic buttons that hold the thing on the servo arm tend to pop off in flight under high load. The screws tend to vibrate loose which allows the pushrod to slide freely. If you use Lock-Tite and the metal keeper instead of the plastic one... and you know what you are doing, then they can work OK, but I've seen too many beginner's planes lost due to those things.

You will see devices which look like the GP Screw Lock in photos of some of the 1/3 scale competition aerobatic aricraft. They aren't the same thing. The ones used in the competition aircraft are much higher quality. (and more expensive)


Ball links are a different matter... if you use a bit of Locktite on the ball retaining screw, then they practically never have problems. R/C Helis use LOTS of ball links. Nearly no slop in the linkage and high reliability. Lose a linkage in a heli and you lost the heli, so we don't mess with stuff that doesn't work.


Engines... OS FX series is great. Thunder Tiger Pro series is very good (95% of the power of the OS FX at 1/2 the cost, and they last several years) Actually, there are many good engines out there.