Theme/Plugins for a subscription auto renewal

Hi.
I am working on a small project for a electrical maintenance contractor. We need to set up a site to allow customers to register, login and pre-pay for any services they want. For people who want to get monthly services, there should be an option to auto renew subscription at the end of every period and option for customers to opt out of the subscription before it falls due.

can anyone suggest an ideal theme/plugin for the same.

Shaju