I get this question all the time: what's a good plane to turn into a UAV? The answer is that it depends on your needs, your budget and your RC skills. But here are some good electric candidates:
For RC beginners:
The NextStar (see above) is roomy, slow-flying and comes with everything you need (including a RC flight simulator). It even has its own rudimentary flight-stabilization system with a Futaba PA-2 optical co-pilot.
For DIY'ers on a budget:
The $110 SuperStar is a nice-flying four-channel plane with enough room for an autopilot and cameras strapped below. The ARF kit comes with a brushed motor and NiCad batteries, which are enough to get you started. When you're ready, you can upgrade to a brushless motor and LiPos. This is the plane we use for GeoCrawler 2 and will also be the basic platform for our ArduPilot-based UAV. You can hand launch it in a park, or take it off from a runway at an airfield. It's tough and can handle wind. All and all, a really comfortable plane to work with, especially once you upgrade the motor and battery.
[Note. This plane appears to be discontinued. You might want to check out the NexSTAR Mini EP as a replacement. It's not quite as good, as it's more expensive and has less interior room, but it does the trick]
For those looking for long flight times:
The Aero-Master is a powered glider with a pusher prop, which means no propellers in the way of your cameras. This is the aircraft used by Marcus UAV.
For those who want to carry heavy, high-resolution cameras, with unobstructed views:
[This one appears to no longer be available, although a larger gas-powered one still is]
For an all-around great first UAV platform:
EasyStar. The classic. Easy to fly, hard to break and plenty of room for electronics. Works best with a brushless motor upgrade.
An even cheaper variation on this, with the helpful addition of ailerons, is the Dynam HawkSky. Well worth considering as an EasyStar alternative,.