400 is your motor size, which means you need a 400 size brushless motor, Here's a good package from electrifly
http://www3.towerhobbies.com/cgi-bin...?&I=LXRNF8&P=7. You also need a LiPo charger, and the right prop for your application, various other building supplies as well. If you need more help don't be afraid to ask, the only dumb question's are the one's not asked! Good luck!