There is no "
huge disadvantage in Google search rankings" for non-encrypted sites. That is a complete myth. I know because I have been through all this with several sites. If anything a site's rankings will decline slightly as all the 301 redirects from the non-SSL to SSL protected URLs take effect. If that is the only reason you are doing it then you're wasting your time and money. You should be more concerned about your visitors' privacy and transmission of personal data, or protecting your own admin logins to your site's back-end for example.
This has been discussed here before:
https://www.gpwa.org/forum/https-goo...ce-226547.html