Re: Long range wifi adapter
Don't know about wifi adapters for computers, but I can completely recommend Ubiquity WiFi APs. They are surprisingly cheap for what they offer. I've seen 2 APs ($90/ea) connected to a pfSense router handle traffic for 50+ people across about an acre area. The end-user devices where not altered in any way.
It is possible to setup 2 Ubiquity APs as a network bridge with direct, fairly long distance connections, and proprietary bandwidth between them. Of course, this config doesn't allow end-user client access to the wifi, another device (AP/router/wired ethernet) would be needed then.