if you want to convert one...try the tutor from greatplanes...put a AP wasp .061 on it with a 2OZ. fuel tank and micro gear...flys like a large trainer,but half the size...
http://www2.towerhobbies.com/cgi-bin...?&I=LXVU19&P=0
http://www2.towerhobbies.com/cgi-bin...?&I=LXSD22&P=7
oh i forgot to ask...are you wanting to build one from a kit???what size of field you have to fly in???
john