a long cable run (without a repeater) won't work because of the 100meter rule, (A wire is a wire, and a signal is a signal, the biggest problem with long distance runs is that UDP packets can collide as their transmission is not guarenteed.)
if you do get a repeater, I wouldn't even consider using patch cables, just buy a rol of cat 5 wire and make up your own,
have you thought of a fibre optic cable? (can make kilometer runs)
As for the wireless, it's a very interesting idea,
I'm not sure that this will work/be possible, but if anyone can find details the the tramsmitting power of the base stations/cards and the gain of the dishes, I'll do the maths and tell you whether it'll work.
IMHO, a laser link will be your best/safest bet, it will need to be installed professionaly, but will be very discrete, and will never sufesr signal problems on account of weather.