RE: upgrade to Brushless
A small foam Cessna model just under 1lb. in weight would fly well with any number of different brushless outrunner motors.
Look for something in a 28mm diameter, 30mm length size rated between 950kva and 1400kva. Match it with a 12 amp to 18 amp ESC and a 2S or 3S LiPo battery in the 500mAh to 800mAh size range. Try a few electric slow flyer props in the 8" to 10" diameter range to find the size you like best.
Good luck and good shopping!