The electrics part
Aw, yes, the electrics part. Not the easiest thing to figure out.
For the small compact wings, you need small comact gear. The smallest conventional gear may not have the range you need. The GWS tiny receivers (4.6 grams) have limited range and glitch. I like the Cirrrus MRX (6.2 grams)have a much longer range for the extra gram of weight (about $25 with crystal). The hitec H-55 servos are small and light, yet are strong; the gears don't strip as easily as the 6.2 and 5.4 gram servos.
If you go with Mini Speed Wing, you get the motor and prop; all that is left is the ESC and batteries. If you read through the thread on the MSW, there are notes about the ESC (2 to 5 amps - look at the Pixie by Castle Creations) and recommended batteries. I like the LiPoly cells; I was an early adopter of LiPoly technology, and am glad for it... You need a special charger and they take a hour to charge, but they fly forever. They have 9 times the energy density of nicads.
Have fun.