I'm an experienced IT Director, mostly speciallized in IT Infrastructure, IT Security, Databases and process automation. I managed teams and operations in many datacenters during my 25 years experience.
I just finished a project very similar to this one, using the NoSQL database Elasticsearch , which is open source, the full suite, named ELK would fit your needs, and I could configure it.
There is another module that comes with ELK , named BEATS, specialy designed to capture logs from many many systems, and customizable to anything.
I think that the ELK databse server would take no more than 2 - 3 days. and log ingestion from Windows events should take 1 to 2 weeks depending on quantity of log sources.
The firewall bluecoat and ironport boxes should take some more time, because there are no previous templates in BEATS yet (so we will have to define the event capture for this devices), I will put all the timings in milestones so we can make some cashflow during the evolution of this project.
Let me know If you have any questions/issues on my proposal.
Best Regards.
Gabriel Neumann