Setting up a WISP without lots of spare pinga's is almost impossible. The routing equipment, DDS connections etc... all very expensive. I think DDS used to be $1,500 a month per termination point just for 128Kbps.

As for the Linksys, I don't know much about thridy party firmware or anything about Linux. But I love the Asus WL-500G because it offers simple static routing on ALL ports including the WAN interface, not just the LAN switch side like most others.

I like the Asus 138 adaptor even more. It comes with software to run a PC as a software Access Point, when coupled with bandwidth managing software means complete control of traffic to each node. I don't know if the Asus 138 card supplied software allows for it to do radius or anything though in AP mode like the wl-500. Biggest problem with most AP's is the limitation of 32 client connections maximum. So if 32 are sitting doing nothing, no one else can connect either. That's why I like the Asus, just daisy chain them and set up static routing between each AP on another channel.

I remember Linksys in router mode used to still have a firewall activated on the WAN adaptor which was really anoying a year back. Maybe they've fixed that since?

I'f you're real serious abtuo a commercial venture, check out the all in one hotspot solutions with user accounting and bandwidth control from d-link etc...