I highly recommend SSLMate too. Buying a SSL cert via CLI and automatic SSL renewal and updates via cronjob make it awesome.

Not to mention it has configuration templates that make getting a best practice config for almost everything you would use a SSL cert on. https://sslmate.com/blog/post/sslmate_mkconfig

Another vote for SSLMate. Used them recently and was stunned at how great they are. Definitely an SSL company for developers/sysadmins (in a good way).