Yes, you can buy a certificate from us. The cost is $30 per year. Our certificates are provided by Geotrust. The install of your certificate is free and you also need to buy a dedicated IP which is required for the SSL installation.
In order to get started you need to generate Certificate signing request via WHM -> Generate CSR request in the SSL section. Then open a ticket with us and provide us with the CSR you generated so that we can issue the certificate. Please note that 1 certificate works only for one URL (www.domain.com and domain.com are different URL's and if you want to access both https://www.yourdomain.com and https://domain.com you will need 2 certificates).