Looking for “snapshot” of network

I’m looking for a tool (hardware or software) that will give me a quick accurate snapshot of my LAN – Bandwidth usage, top talkers, errors/collisions, protocol usage percentages. If the solution is software, I can put it on a laptop and place it atthe appropriate location on my network. I have just purchased a Cisco 4003 for the core of my network. I have a limited budget (don’t we all) of $1200 or less. -Thanks