Internet proxy/reporting

Hi guys,

I'm in dire need of a proxy and reporting tool for Internet for a Windows based environment.

Basically I need to allow/disallow certain users (or groups) internet access, and be able to produce a report of internet useage/sites visited/times on a user (or group of users) when asked by Management.

Does anyone have any good suggestions? Ideally I would like an outright purchase solution rather than a yearly subscription or CAL licence model.

Thanks in advance,

Gav.