Yes, you need 2 wap11s. As pointed out in the previous post, one wap11, pigtail, and antenna go on each end. Otherwise there'd be no way to maintain a link at that distance, with a standard 32mW output of a standard card. Also, use LMR400 coax, when running to the grids. Don't use more than 50' of cable. [I'd recommend 20 or less]
Don't quote me on this, but last I checked, wap11's with 24dB gain antennas are legal. I went to linksys's site to double check this, but I couldn't find the specs of power output on their pdf anymore for some reason, so if you're really concerned about it, you'll have to check into that. For this type of setup, you can crank out up to 4 watts. If you're not quite sure how to calculate this:
appowerindbi ^ (1 + ((antennagainindbi-signalloss)/3))
The signal loss is where you factor in loss from cable and stuff. Factor in 1 to 2 dB for every coax connection. Look up the specifics on your cable online somewhere. Even though it may be category 400 cable, it can be different from one manufacturer to the next.
Ya only have to worry about all of that though if you're really concerned about the fcc knocking on your door. The biggest thing is, pick a channel that nobody in your beamwidth is using, and you'll be fine. Get channel 6 if you can get it. It's right in the center of the whole band, and is what antennas are tuned to. It'll help your signal a bit. Also, you may want to experiement with various polarizations. . . If your signal is funky, turn your two parabolic grids 90 degrees, and see if it's better. Play with it. Just keep in mind, that whatever direction one antenna is going, the other one must be pointed the same, otherwise you'll have almost no signal.
Anyway, bottom line is, get one ap, one pigtail, one chunk of coax, and one parabolic grid on each side. [You can get the pigtail, coax, and grid from
http://hyperlinktech.com, or
http://www.fabcorp.com. fabcorp tends to have cheaper pigtails, but hyperlink has the best grids] As for mounting all this, do whatever is conveinent, and offers line of sight. If it's not line of sight, it'll work pretty poorly, if at all. If you have to put a 20 foot pole on top of your buliding to get it to work, I strongly advise it. At these frequencies, electromagnetic waves are practically like lasers. [Not quite, but if you imagine them that way, it'll work better for you] They don't like to bend around stuff. Everything has to be perfectly aimed at these distances. Also note: Don't just point the antennas visually and be done with it. Even if you had it dead on, sometimes this doesn't always offer the best signal. Plug an orinoco card into the antenna with netstumbler running or something, and watch the levels to get the best signal.
If you wanna get really technical about it, later we can talk about adjusting your standing wave ratio, but it's really not necessary at this point, considering the antenna is commercially made.
Have fun, and post with any questions.