Yes, that's technically doable. Although, if I were you in this position, I wouldn't mount the AP on the porch. I'd put a wireless bridge between the porch and clubhouse, trying to get above traffic level if possible (roof to roof). Then put your AP (or switch/hub) in the clubhouse. In fact, I have had almost this exact situation - two school buildings with 200' and a road between them - and that is what I did.
When running the CAT5 you should get 'direct burial' cable. You can bury the cable, or run it on pole in the air because it is UV resistant (the standard PVC plenum or riser cable is not) and filled with a gel to prevent water from getting in the cable. But it still wouldn't be a bad idea to get it in conduit if possible.
A wireless bridge is two devices that link together and will only associate with one another, each locked to the other's MAC address. The advantage to this is that you don't have to have your client machines trying to talk to an AP through a few walls and on the other side of the campus, and the wireless link - if you have clear line of site and are above the traffic - will be rock solid over that distance. It will perform as good as a cable at broadband internet speeds.
We've done something similar for temporary trailers at work, but "on the cheap" (as opposed to the commercal grade $500 bridge link radios). We buy two AP that are capable of bridge mode. We then took the innards out of the AP plastic case and hot glued them to the back of a 12" x 12" x 8" weatherproof, UV resistant PVC electrical box. We drilled two holes in opposing sides of the box and mounted the antenna connectors from the AP case in the new PVC case. Screw on the antennas and wrap the bases in splice tape. Then run the DC power and CAT5 cable through a hole in the wall and then through the third side of the box. Seal up the penetration with silicone and hang the box on a wall. Do two of these and you now have a weatherproof outdoor wireless bridge for under $100.
Make sure the PVC box is rather big so that there is plenty of air in the box. The board can't breath in that box so you have to have enough surface area that the box can radiate heat as fast as the board can dump it into the interior of the box. And put them in the shade if possible, like under an eave.
Oh, and be careful when buying something that says "wireless bridge". I have bought Linksys equipment that said wireless bridge but wasn't really. The were actually client adapters. But you could bridge the network between a non-wireless equipped piece of hardware and a wireless AP/router so they called it a bridge.
Hopefully that was helpful instead of boring or confusing.
Josh
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