Re the throttle, if your using LiFe or LiPo 2 cell backs for the servos, just ensure it's a suitable high voltage servo also. It does not need to be strong, that said, I'm using these, as a guy my dad flew with up where he lived used these in his 50cc Sbach on everything (control surfaces also), and flew the snot out of the thing for ages without issue (still none to date from what I've been told).
I've put the ones I have on my choke and throttle as at $10 for a HV servo (7volt rating) I'm not too concerned - I also will have remote engine ignition kill setup on my transmitter should something ever go haywire (not that I'm concerned it will).
http://hobbyking.com/hobbyking/store...0kg_16sec.html

Still, I better go re-check my elevator install on my Sbach. I have it with the glue drying at the moment, as the last time I did it the cursed epoxy I had went off WAY too soon, and I had to VERY carefully cut it out this morning so I could get all the measurements just so as I am completely anal on ensuring it's as perfect as I can get it (1mm out is 1mm too many for me!)
This is my baby: