2 wireless bridges as suggested by TQ2K is a good approach to avoid interference with other wireless. However, as a cheap solution you may want to give a try to the Belkin Pre-N Wireless router. I bought one this summer and used it for 10 days and was amazed by its range. I tested it at 400ft from my 802.11 G laptop card and still got a pretty good signal. It gave a much better range than any other wireless router I have tested to date including the latest Linksys and Netgear. The only reason I brought it back and replaced it with the Belkin N1 router was because VOIP did not work well on the Pre-N. They may have fixed this problem since though.