Hello Neil
I am not sure if you have heard of the legendary Damian Peach.
http://www.damianpeach.com/
His site has some great info on the cameras he uses...the results speak for themselves.
I used the Phillips TouCam pro with great results. Sadly it doesn't work any more and i am also on the market for the next upgrade.
I have heard good things about FLI instruments too.
http://www.flicamera.com/