I spent the last 3 weeks searching for a good hardware firewall solution for my company, I end up with two solutions and really do not know what solution to choose.

the first solution is Cisco ASA
the second is fortigate

I like the filixibility of fortigate firewall, I already has a small unit and test it.
and I have cisco PIX 515E firewall and already test it, it is a great solution specialy when it is integrated with websense for URL filtering.

the problem in using PIX with websense is the huge amount of users in my company "actually it is a university". we already have 5000 PC in the univ. and in a normal day, all the computers can run at the same time, and that means that there is a 5000 different IP address running at the same day, when I contacted websense company to ask about the licsense, they told me that it costs 9$ for each user "each different IP", and that meens 45,000$ per year !!

what we really interest in is a basic firewall with URL filtering and IM/P2P blocking with a good reporting service.

My questions are:

1. what version of ASA or fortigate do we need to buy to serve 5000 different users?
2. if we buy the ASA, we need to buy the Anti-X Edition with "Cisco ASA 5500 Series CSC-SSM-20 Plus License" subscription each year, do we need to buy this liscense for 5000 Users to enable the URL filtering to all the users ?

Sorry for my bad english

Thanks in advance