I don't think you're getting the point. *WHAT* are you looking for? UTM means different things to different people. If all you want is a packet firewall and NAT with URL caching, depending on how many people you're looking at servicing, just about any box on the market will do it. The only additional thing you need to add is either something like squid or polipo.
-- http://www.glumbert.com/media/shift http://www.youtube.com/watch?v=tGvHNNOLnCk "This officer's men seem to follow him merely out of idle curiosity." -- Sandhurst officer cadet evaluation. "Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." -- Gene Spafford learn french: http://www.youtube.com/watch?v=30v_g83VHK4
