Since the Linksys firmware for the WRT54G isn't really flexible and the Sveasoft firmware sucks cause this license issues I migrated all my boxes to Openwrt.
Openwrt is a minimal firmware with support for add-on packages ... this makes it more flexible for personal use.
At the moment one box, which runs on a hardwarerevision 2.0, works as accesspoint, the wan port is bridged to the wireless interface and works as uplink with static ip configuration (no pppoe and stuff). The lan switch ports are working as bridge together and its not connected the other interfaces ... so I can easily investigate whats happening on the network and the important thing is, I can build up ACLs to control, whats going over the bridge.
The second box runs kismet_drone to monitor which clients are trying to connect to our wireless network and get them down.
Both boxes are running the stable branch of openwrt and I'm really happy with it. It works like a normal linux system and there isn't any need to make use of a webinterface.