Thanks Paul and Graham.
I'm actually fairly familiar with North West Cape. That's a long way to go for seeing, though - sometimes the hike to the deep of the back yard seems like too far. And I agree big cities are out, besides I can't afford the real estate. I don't think I'll need to worry about cloud statistics, though, as I usually seem to bring my own.
I hadn't really thought about whether the camera allows air into the electronics - I'd been concentrating on the optics.
Thanks again everyone for all the advice and suggestions.