What Oil To Use
If there's a Honda motorcycle shop nearby, you can use Honda HP2 synthetic for 2 strokes. I use it at 32:1 ratio, as recommended on the bottle. I'm sure you can find other all synthetic oils at the cycle shop.
A lot of people use Amsoil at 100:1, but Aircraft International will void the warranty if you use that lean an oil ratio. Amsoil also makes a 50:1 oil, called Amsoil 2000-R. If you want to use that brand, use the 2000-R product at a 50:1 ratio.
More oil = more power, cooler temperatures, better corrosion protection during storage, and less engine wear.
3W also distributes their own brand of synthetic oil. For that you contact Aircraft International or Cactus Aviation.
The lowest cost synthetic is Mobil MX2T - available at the auto parts stores for $3.50 / pint. I've read about good results from the MX racers using this oil, but haven't tried it myself.