PostgreSQL is supported by cPanel and can be administered through cPanel's web-based interface. Generally, you can install any software you would like on a cPanel VPS. However, cPanel must be compatible with the software for you to be able to administer it through cPanel.
RVskin translates cPanel into Russian and a large number of other languages. RVskin is available for $3 monthly on the cPanel VPS 200 and 300. RVskin is included with the cPanel VPS 400 hosting plan.
Please let us know if you have any other questions.