Jim,
Although you can use just about any finish material you like for electric you should watch the total weight. The biggest impact on weight with electric is the battery. Since there isn't to much you can do for a reasonable price on battery choice, finish is the next big weight hit. A couple ways to approach this, simple is cover the wings and tail surface with film then paint the fuse and trim. If you are very careful with the film you can get a very respectable finish at very low weight. You could also do the whole thing in film but doing the fuse can take a bit to get comfortable with.
If you want to paint good old Brodak or Sig dope will be the lightest, good thing is you can buff it out and not need to do "death paint" and it will resist problems from IC guys as Tim said. Check out the Windy videos on YouTube for how to finish with dope.
Best, DennisT