Hi,

I'm designing a mid to long-range (5-10km) UAV that needs to carry a payload with a mass <2.5 kg. It needs to stay up in the air for at least an hour. I know some of the components going into it, but I'm not sure about a lot of them. I also don't know what airfoil I should use. I understand aerodynamics, but I'm terrible with electronics. I need to figure out all the components before I can find a wing design. These are the problems problems that I have:

Airfoil:
- Requirements:
- Maneuvering speed at ~40 knots, Vne at ~60 knots.
- Predictable stall speed, preferably as low as possible.
- Low drag
- Not too thin

Electrical Components:
- Known:
- 3DR APM 2.6 Autopilot
- Ublox Neo 6m GPS / Magnetometer
- Hobbyking OrangeRx Open LRS 433 MHz 1W
- Airspeed Sensor
- Unknown:
- Battery? How much amperage + voltage would be good to power everything for 1+ hours?
- Motor? Climbing power isn't exactly an issue but I need to be able to fly in a headwind.
- BEC?
- ESC?

Oh, and I'm on a budget of $400 so don't go crazy :P

Thanks