OK, after rifling through the local Maplin £1 or less bin, I found 2 x Massive 6v dry batteries, at 50p each. Needless to say they were purchased immediately. After building a little header one of the batteries now connects to the PIC control board and powers the PIC circuit and the camera nicely.
A bit of eBay bashing and I found a waterproof box, which with a small hole drilled, for the lense, and cable ties for the camera, now house camera, battery, control board and some foam to hold it all in place.
After programming the PIC to use 2.5 minute intervals, marking the box with "DO NOT REMOVE" and my mobile number, in the hope of avoiding theft (and bomb scares), late Saturday night I shimmied up a lamp post and strapped the unit on to record the local 10K run. I think the end result is pretty good, check it out in the links.
This is the first time the camera has been used in anger, and it worked nicely. I think the next test might come this weekend, I am thinking 30 second intervals (12 hour run time) and strapping it to the side of my C90 for a trip to Matlock and the Peak District. We will see how it fairs....