I have been flying electric aircraft exclusively for the last 4yr. You will probably want to go with the rffs-100 system, utilize lithium-polymer batteries. I have seen the skeeter micro plane that uses the rffs-100 and it flys very well. You can get more info at www.slowfly.com
on this system. I am assuming that the system needs to be proportional. The rffs-100 system utilizing the actuators is extremely light. Are you wing area limited?? If not consider a biplane or a tandem wing platform utilizing contra rotating inline props similar to the do-335 this will relieve torque problems and allow a larger disk area for better power transfer, of course remembering that more motors requires more availiable power which causes more weight which requires either higher speed or more area. Last but not least, parasitic drag on small aircraft is a killer so keep it to a min. Boy what a balancing act.
Hope this helps