You're better off getting WF100 cable Mike. Possibly even 'shotgun' (a dual cable) so that you don't have to replace the cable in the future if you ever decide to get SKY+ in there. Also, it may be worth putting an ethernet cable down when you do it so that you can stream films in the love nest cabin.
WF125 is a better cable but it's very bulky (and much more expensive), if you choose to use it, I'd recommend connecting WF100 to the sky box and connecting the WF125 to the WF100 simply because it's weight may physically damage the sky box connector.