This is most definitely a question for Cris. But I'd agree with Andy and Shonky.

However in the past BT would put a line in with the master socket dangling from a telephone pole and I've had ISDN's installed in the middle of a car park. If you're happy to have your master socket in a box 200 meters away from your home, you might be okay.

I'd say go with the thicker gauge stuff, but if you're already miles away from the exchange, you're probably starting out in the noise anyway.