Any of those will do what you need. I use a Netgear RT314 router and have been pleased with it (though I did have one fail inexplicably and had to replace it).
The default setup of the routers should work fine, you should be able to just plug-in and go, however you may need to make some adjustments. AT&T requires that you register the MAC address from the device connected to the cable modem, either by calling in or by having the install tech provide it when he calls in with the MAC address for the cable modem to be provisioned. Usually they want the MAC for one of your computer NIC's. You can provide the MAC for one of your PC's first, and then later clone that MAC onto the router's external interface so you don't have to call in and provision the one the router actually uses (make sure the router you choose supports MAC cloning if you want to do that). This is also called "spoofing" the MAC, which the RP114 does support. The advantage of this is you can just plug the cable modem directly into that one machine later if you need to call tech support, who will only help you if you have only a single machine connected.
In order to run a web server you will also need to configure port forwarding in the router, or "SUA Server" as Netgear calls it (Single User Account I believe it stands for, indicating you're only getting one IP on the external interface). Keep in mind that AT&T does not allow servers on their cable network, so if they catch you, they can cancel your account. They may also simply block the standard ports (80 for web) from being accessed from outside their network to inside (which will not affect your web browsing, only someone accessing your server on that port). So you may end up needing to run the server on a non-standard port.
Other than that, you just need the obvious, like network cards in the PC's and cabling. The routers will all perform DHCP services so that the PC's and game boxes will receive IP addresses automatically.