This is exactly what we did. I bought a mini, replaced the hd with a 128gb SSD and then maxed the ram out at 16gb and installed CentOS on it. The machine works

This is exactly what we did. I bought a mini, replaced the hd with a 128gb SSD and then maxed the ram out at 16gb and installed CentOS on it. The machine works great and if we start getting a lot of traffic, I'll just get another one and move postgres off onto that. At some point if the need arises, I'd love to look into getting a thunderbolt nas for the db storage. That would be fun.