gregober,
I have multiple sites running pfsense 2.0RC1/2 authenticating against external (public) RADIUS box(es) using the built in portal. Remote users have the ability to log in, and create users and groups for their site.
As far as daloRADIUS:
Tested daloRADIUS in a Xen VE today with success locally. I plan to migrate this Xen VM to a public farm as well as test the accounting attributes along with AD integration when I get time. I don't see why this would not work, dalo is nothing more than a great front end for freeRADIUS.
I have a Mesh build on the table integrating C15C0 Wireless Controllers, and I plan to use pfsense as a gateway, daloRADIUS & paypal for payments. This build could pan out, or become a tangent… either way, I may be interested in assisting with paypal integration, it looks like you're going to be deploying a large scale system ;D