|Actually, now that I think about it, a wireless capable SOHO Router with 4 LAN ports would work without the switch since that gives you enough LAN ports for the AP's.|
First, you get your router connected to the internet and working. You then configure the wireless network on it. Then you connect your 4 AP's via ethernet cable (be it Cat5e or Cat6) and configure them.
and one more question: in each floor there are 4 users so i want every access point to have 4 user accounts to track every user's internet usage separately. is that possible?
Sorry but I can't help you with this. We don't track usage at work for employees so I have no experience with that. The best advice I can give you on this is to look at different SOHO Routers and AP's and see if any of them are able to track usage. If they are, go with those devices (remember, you can always configure a router for use as an access point)
To be honest, I'm not sure why you'd want to go through all the extra hassle of tracking. I'd charge a flat fee and stick something in there to limit bandwidth in case any of your users, or their children, try to hog up all the bandwidth using file sharing app's like limewire.
Regardless of pay-for-play like you're talking about, it's not fair to the "regular" users to never have bandwidth available to them because you have a couple clients running point-to-point software (like limewire) that hog all the bandwidth.
Trust me on this, if I was a client of yours (ie: lived in your building) and could never get bandwidth because you don't limit people like that, I'd be all over you like ugly on an ape.
In the end, I'd just get my own provider and not bother with your service. Chances are I'd get better bandwidth with less hassles for less money. Keep in mind, there are already a lot of ISP's out there providing internet and you're trying to reinvent the wheel. The ONLY benefit you could provide to people in your building is if you can give them good bandwidth at a better price than they could get from any other provider.
Just some food for thought before you go spending a bunch of money on this. Personally, I couldn't be bothered as it's just one more thing you have to take care of in your condo's. Better to let them get their own service from whomever they want and you don't have the hassles of calls at 3 am because, "There's no internet and I want to check my email"