I live in an old farmhouse, with hardwood floors and plaster walls. My ISP enters the house in the back left corner, on the second floor. I plan to purchase a new iMac, and want to place it in the front right corner of the house, on the first floor. The diagonal distance will be ~50 feet. I want to use wifi for the new iMac. Any advice on how effective it will be over this distance? My thought is to use an Aiport Extreme or Express at the base, and a Time Capsule halfway between the base and the iMac. Thanks.