Furthermore, your profile suggest you work for a pump and dump penny stock company (basically a scam). If your employer is paying you in something other than cash, you need to walk away asap.
There's lots of video CDN "solutions", and it's almost always cheapest (even after labor support) to DIY with bare metal at very large scale. If it were me, I would eval video CDN shops using tsung test cases wired up as nagios checks. Gotta make sure their stuff stays working.
A payment gateway once mistakenly deployed API changes to production without notice. Trust no one.
Anyone evaluated? http://live.bittorrent.com
If you simply need to deliver files or live streams, without needing to provide complex functionality at the edge (various kinds of protection, geo blocking, or pay-per-minute), and your traffic patterns are predictable - it's often cheaper to build your own solution. Once you start thinking about backbone and colo redundancy, deploy in different countries with contract commits - things get expensive very quickly.
The beauty of using a massive third party delivery service isn't performance, it's elasticity. Just like with the web apps (frequently hosted on DIY systems) that go down as soon as the link goes up on HN - being able to absorb traffic spikes without failing (and without forcing you to commit to a higher tier for a year) can be very valuable.
Setup enough identical boxes with each of Squid, Nginx, Varnish, trafficserver, etc. and evaluate each with basically the same traffic and however much tweaking.
Simple caching works for images, but doesn't work for large video files, for example (look at latest financials from public CDNs - they are all bleeding cash).
It's really not that simple as testing a box to see which setup works best.