So what goes between the antenna and the Linksys box?

As little cable as possible.

Use LMR-400 cable. Get Radiolabs to make you a custom cable up to 40'
long.

Do not make this cable very long. DO NOT run it down an entire mast. The
dB loss will be greater than you want for WiFi. It's better to use an
enclosure that lets you keep the WiFi gear as close to the antenna as
possible. No, amplifiers will not work as effectively (at least not without
using VERY expensive ones).

-Bill Kearney