I must warn you that if you do this you will shutdown a large area by causing interference that will likely get you visited by people you do not want to have as guest. At the freqency the units work and the way they work this is a really bad idea that if you do unless you leave in Kansas on a farm with no one else for miles you will I repeat you WILL cause illegal interference and will have compliants filed on you. You will bleed on most of the 802.11 band and since you can not hear the other transmitters you will not shut up to allow them to transmit. This will shutdown all wifi in your area and there will be very unhappy people. It also will not be hard to find you.
100mw on the built in antenna is legal and FCC certified. 1 watt on an external antenna is gonna be costly and I am not talking about your amp and antenna
I can cover 5 acres with the stock ver 2 unit as long as I put it in the clear and up off the ground.
RJ