Advice on an enterprise management/NetFlow analyzing tool or suite

Hi There,

I've been tasked by my company with finding the best option regarding the title of this post.

I'm relatively new to something of this degree so I've become a bit despondent in my findings.

I'm looking for something to monitor the overall network traffic flow, analytics , logs, mapping and device inventory of a contracted business. The business is a very big private school and budget for licensing is quiet lenient.

School has a Server with dedicated VM's which could be used to run the management system.

The options I've looked at are SolarWinds, Site24x7, Datadog, Progress WhatsUp Gold, Zibbex and ManageEngine OpManager.

I'm looking for preferably an agent-less solution.

On-premises or SaaS is best for this company.

Please can I get advice on which solution as I fell quite lost with all the options available.

P.S. If this post breaks the rules, before deleting please advise where I can ask.