Router options for a Non-Profit Organization

I am in charge of the computers and network at an non-profit organization. We have about 12 computers on a Bell Sympatico Business Internet connect. We have right now a WatchGuard Firebox X15 router/firewall that was installed by the previous System Admin. Out Live Support has expired and they want a handful of money to renew it. I am looking into getting a new router for our network, hopefully a Linksys WRT54G-L. What are your suggestions?