A wireless access point does not do NAT, at all; it just plugs into an already existing hub or switch and allows that network to be accessed wirelessly. These are useful for extending the range of a wireless network, or useful if you prefer to use a Linux or BSD machine to do your routing for you.
Nowadays a vanilla access point is probably more difficult to find, and more expensive than a standard wireless router, which would eliminate the need for any machine to be on 24-7 doing NAT; you would plug your cable modem and wired machines into the router, and it would handle everything else on its own, including stuff like DHCP.
Find a wireless router for $20-30 and save yourself a ton of aggravation. Only reason someone would want to do what you're doing is if they preferred using Linux or BSD for their firewall/NAT; since you'd be using a Windows to do your routing it's kind of pointless. Not to mention whenever your brother reboots the entire network's access to the Internet goes along with it.
Thanks bedouin. I guess a wireless router is exactly what I thought an access point was. So I need a wireless router and a few wireless cards.
Thanks all
