RE: Payload Question
That camera is just too much to ask for a pair of 25's. The wing area is just not enough, period. To lift that kind of woight you will need at least around 100 plus inches of wing span. And quite a bit of engine. Say 4 cubic inches or so. The vibration would make taking pictures tough.
You have the right idea. A small servailance camera and a telemetry module would do it. Look in RCM and MAN. I have seen package deals at a reasonable price. I would however swap out the 25's and go with 32's or so. The Irvine 39 I think would be a fantastic choice. Same size as a 25 and the power of a 40. Good luck with the project.
Mark Shuman