It's a little more expensive, but a SonicWall TZ170 can do all of that. Has a DDNS client built in as well as Static DHCP, Firewall, and Bandwidth management (by ip address range or port). If you'd like to log in and take a look at one of mine, PM me. (note: linked one is not a WAP, just a firewall/router. They make one with wireless also for a few bucks more.)

I'd imagine that a WRT54GS can do all of that with upgraded firmware, but I've had mixed results. Of the three that I've upgraded, one of them bricked on me for no apparent reason. I was not able to recover it even using the hardware reset methods on the net. One of the others was never quite stable. The third one worked great.