a "conventional" 802.11g WiFi wireless network? You mentioned a shared phone line and 1,000' separation, but you didn't say much else about the physical layout. Standard WiFi is good for a couple of hundred feet, except under ideal circumstances and using extreme efforts, e.g., the recent WiFi contest in Nevada where the guys got a range of 120 miles (yup - miles!). I set up a system on a farm of over 150 yards between the house and barn using just a 3-year-old Netgear wireless router in the house and a high-gain Hawking USB adapter on the barn computer. The "features" that made it work were: a) a parabolic reflector on the router antenna made from cardboard and foil (instructions and patterns available from www.freeantennas.com), and b) a clear unobstructed line of sight between the house and barn. The router is on an upstairs windowsill facing the barn and the antenna of the barn system points out the barn window toward the house. The signal is strong enough that I think it would have worked at a much longer distance. I was working with an old router that I had lying around, but if you were buying new equipment, you might consider the Belkin Pre-N line. People say it has very good distance performance.
Just an idea for you