Mic Cable for the Outdoors?

["Charles Veasey" veasec]

Hello,

I'm getting ready to buy some long microphone cable so I can get more 
distance from the recording location and myself. I'd like to work with 
100 feet of distance, which cost as much as $500 (for stereo). I don't 
want to spend this much, but I don't want to buy something cheap, as I 
might to need to run it along snowy or damp ground.

Please, a couple of quick questions:

1) Do you think the audio signal will be compromised if I run 100 feet 
of 5-pin stereo XLR cable as opposed to two mono cables? (5-pin is more 
ideal, because I am using a Rycote Windshield system)

2) Recommended online source for buying mic cable?

Many thanks,
Charles