With the upcoming GDPR requirements looming, you will not be able to afford to learn from your mistakes.
To partially echo Jeff, your first task should likely not be deciding upon a platform. You should be determining security, usage, and continuity. Write your business rules. Review them. And please, please hire a professional that can help design this system.
Michael L John
If you assassinate a DBA, would you pull a trigger?
To properly post on a forum:
http://www.sqlservercentral.com/articles/61537/