I love linux and the freedom it gives you, as well as the flexibility provided my MySQL. Concurrently, I also prefer to avoid windows, and the majority of Microsoft products wherever possible.
In the past, I used MySQL on both CentOS and way back in the day Red Hat Linux. In both cases I was using them in conjunction with a PHP website.
Long story short, in both cases I had huge database overhead that required either constant maintenance, or to automate required scripts to be written. Failure to do so resulted corruption after very short time period.
As much as I hate to say it, this game LOVES MSSQL.
MySQL eats resources like candy.
I also agree with theDomo that you would run into several stability issues, at least at first. Its not impossible, but I feel this is a much bigger project than perhaps the OP was thinking.