Due to a concrete floor and my HT room in the basement (with a patio door between the receiver and rear speakers) I am looking at running speaker wire outside. I have vinyl siding and was planning on running it inside the siding. I like in Spokane, WA, where the winters get down to the low 20s for a couple months (at night) and the summers are in the high 80s. The outside wall is a "sun" wall (it's the south wall of my house). Does anyone know of any concerns I would have with 12 gauge speaker wire in the above situation?

Also, where is a good place to buy heatshrink tubing and is there a simple guide somewhere for mounting banana plugs with the tubing? What size of heatshrink tubing is best for 12 gauge wire?

THANKS!