Have you looked at the Ubiquti Nano Station (directional), or Pico Station if you prefer more power with a small Omni-directional antenna, or the Bullet if you want it to be more like the ones you posted? They are much cheaper (under $100)and not as hard as they look to set up. There is a good you tube video of a fulltimer setting one up to do what you are wanting. They are just as powerful.
I just set one up in my RV and it brings the signal to my regular router for me to use everything inside my RV.