All the security you demand!
Comodo checks domain ownership before issuing the certificate. Domain-validated certificates are usually issued in just minutes.
Your PositiveSSL cert comes with free static Site Seal. You can display the seal anywhere on your site, to let customers know they're shopping on a secure site.
The Positive SSL certificate comes with a 7-Day Refund Policy, so you can take time to be completely sure you've purchased the right cert for your needs.