Mirage 550 with Geared Endoplasma/7 cells and 10x7 E prop. Will fly all day on 1/4 throttle, ROG and T&G. Total setup cost:$260 including battery pack (2000nimh). www.goldbergmodels.com
Requires minimum 35 Amp ESC with this setup.
I have a nice green/white one with r/e/t can also be modified for ailerons. Will do sustained inverted flight with this motor and ailerons (or just with rudder if you're VERY careful) Also thermals!