Could I set up a PC with dual rj 45 to be a firewall then send the internet to the wifi router?

Yes you can, but in order for this to work properly you will need an OS that knows NAT, Network Address Translation.

EDIT:

On second thought, doesn't the wi-fi router have some sort of firewall embedded?

Edited January 3, 200818 yr by nitroshift

it does but i would rather be able to determine what websites are blocked and what shouldn't. In the Netgear router I own, in order to block a website i have to block the keyword. It doesn't support block a specific URL.

What OSs are NAT supported?

windows XP has ICS (internet connection sharing) built in, look it up this is essentially allows your OS to act as a router and perform NAT

Edited January 3, 200818 yr by eyeball

Assumming I did it though XP, would i be able to turn off the DHCP in the router and manually be able to give all the computers in the network an assigned IP in the subnet 192.168.0.x?

Also, would I still be able to use the 'Server' to printer from over the network?

XP doesn't give out IP addresses, you will need Windows 2003 Server or some Linux flavour to have IP addresses allocated by DHCP.

Could I use the router as the DCHP and still do what I want?

XP doesn't give out IP addresses, you will need Windows 2003 Server or some Linux flavour to have IP addresses allocated by DHCP

Are you really sure about that?

Are you really sure about that?

YEP! Wanna bet?

XP doesn't give out IP addresses, you will need Windows 2003 Server or some Linux flavour to have IP addresses allocated by DHCP.

Would Windows Home Server do it?

it doesn't by default, but there's an add-in that adds that functionality

http://www.wegotserved.co.uk/windows-home-server-add-ins/