I would use what you know unless what you know is going to cause problems for you. Building a store is unlikely to cause you problems. Take a look at the PHP

I would use what you know unless what you know is going to cause problems for you. Building a store is unlikely to cause you problems. Take a look at the PHP based cart options available and see if they will fit your needs. If they don't then look to see how much work they will require in custom development. If you can easily do something with existing scripts then I would think the savings in time and getting to selling as fast as possible would be best. If you start to outgrow your first CMS based solution then you could always build something totally custom with something like CodeIgniter while your store is still making sales. You might even be able to take the time to learn Python and Django in exploring other options. If nothing you find will work, then go with CodeIgniter (though Drupal is also somewhat of a framework and you could build a cart as a custom add-on) so that you can get to sales as fast as possible.