Network-based Security Solutions

I'm currently researching security solutions for the service provider
environment and figured I'd query the list for recommendations and real
world experiences.

I know network security is a rather large topic, so let me try to narrow
down my area of interest some..

Network infrastructure protection seems to be the topic of most of the
security presentations given at previous meetings, however there's not much
information out there regarding host and subscriber protection via the
network. Specifically my interests are focused on the netflow based
solutions, network appliances (IPS, etc..) and traffic scrubbers. I'm
finding it increasingly difficult to weed through all the vendors out there
who upon closer evaluation are truly only suited for enterprise/small
service provider deployments (less than 1Gbs). Any help in narrowing down
my focus along with real world experiences is greatly appreciated. A
discussion of router configuration, black-holing, sink-holing, and other
types of holing isn't necessary.

Also, I'm also interested in hearing any suggested testing methodologies or
publications that might assist with the overall selection process.