Outdoor Rugs and/or 'breathable' carpet pads?

We're redoing our basement and would like to stain thefloors. It's an old house, so we still have a bit of a moisture issue...water moisture still migrates through the floor slab, as there is no vapor barrier underneath. As such, we're trying to find some rug options that will either a) be water proof (outdoor rugs) or b) breathable.

Target.com has some nice looking/modernish outdoor rugs, but only available online. We'd really like to see it in person. Can anyone recommend some places that carry these?

Alternatively, and maybe a better option...anyone know of a good, breathable carpet pad that we could put any ol' carpet on?

I'm thinknig something liek a plastic mesh...kind of like a dishwashing scrunchie. Something waterproof and breathable as opposed to the regular pads that either stick to the floor, or completely cover the floor and trap and/or absorb moisture.