use a 20 mhz channel, and make sure its centered on a common wifi channel. these units are meant to use wifi as a temporary feature to migrate other platforms to the epmp access platform, thats not natively wifi. not advisable to run them this way. the epmp connectorized and integrated radios can be re-flashed with the cnpilot firmware and will run MUCH better.
5ghz is commonly used for wifi, but not all devices support it, or all 5ghz bands. the narrow beam of the force 200 makes it a less than ideal choice to give wifi coverage over a given area unless its very narrow straight line. its a great radio, but its designed to make a very tight pencil beam traveling from point a to point b. its also able to reach ERIP powers that can damage devices in close proximity to it (ie older cellphones).
here are the purpose-built wifi products:
you can also reflash these products to be purpose-built wifi gear:
if you go thise route, you'll need to pick a sector antenna as well. you can purchase dual pol sectors and use 2 of these radios, 1 for 5ghz, and 1 for 2.4 ghz.
the 2000 foot part, thats a problem for wifi. it's not impossible, but the problem is them talking back to you. generally, 2000 feet is too far. a high gain sector with a radio tx power set to 15 to 18db will give you the best real-world result for that.
an AP that can talk really loud can still show full signal, but the device can't talk back
a cell phone with a 2db antenna, and 15db tx power, gives you a total of 17db ERIP VS a powerful radio like the force 200 that can tx at 30db, plus 25db gain can land at 55db erip (this isn't legal usually, and can damage devices close to it)
in this real world example, you've ended up with a device, the cell phone who can hear the force200 at -60, while the force 200 hears it at neg 88 (unusable) but the phone will you should you full bars (if you get it to show up on the device)
a better match will be a sector antenna and connectorized radio with a lowered tx power to more match your devices so when the device indicates low signal, that will be similar to your uplink power as well.
2000 feet is usually not reliable or quick unless there is no noise or directional higher gain antennas being used. even with a solid sector, and the 1000 radios re-flashed, in most situations you'll have a poor experience to most devices.