There should be a variety of options for paid certificates but I'm not sure that we're in the habit of recommending particular paid CAs. I remember that there is a comparison site at https://www.sslshopper.com/ but I don't know how neutral or independent it is and don't know who runs it.
As another possibility, depending on the nature of your relationship with your hosting provider, folks here have been maintaining a list of hosting providers who support Let's Encrypt
Many of these hosts will take care of getting and installing Let's Encrypt certificates for you, typically at no additional charge, and also renewing them before they expire. For many people that's a more convenient option than having to do it themselves. We hope more providers will offer this kind of service over time.