you can build a quadrocopter easily on your own: german: http://mikrokopter.de/ucwiki/ english but without videos: http://mikrokopter.de/ucwiki/en/MikroKopter yes, quadrocopter are very, very stable, but if you want a stable, really small, 4 channel, indoor helicopter i can recommend you a walkera 4#3b. the full brushless edition...