For kite equipment, I have been happy with brooxes.com gear. At spatial@ucsb, Kitty Currier and I have endeavored to create inexpensive aerial platforms. One of my favorites is the Discavet– a self-leveling rig made from a compact disc, plastic bottle, twine, cable ties, tape, notebook clips, and a toy screw. It uses a Picavet suspension. See: http://www.flickr.com/photos/jaglennon/4590225417/in/photostream/
Gyro servos are now fairly easy to acquire (though about $65-$70/each), and could make for some fun hacking.
Concerning software tools for basic georeferencing and partial orthorectification (to reconcile sensor alignment of aerial images), here are a few I use: