I was in exactly the same situation a few year back. I had a little lan room not to far from my house, so i bought a roll of Cat 5e and got 2 work. I use an ordanary DLink router, I got a max length of up to 125m, after that the packet lost was quite heavy, the latency also went up a substantial amount. I used noramal 15m lengths of PVC pipe to secure the line. I used normal silicon sealer to close the ends up, also used PVC gue to gue the 15 PVC pipes together. So there you have it! works like a charm!