Hi Chloe,

I would stay away from WooCommerce for any kind of complex e-commerce store because I don't think WordPress is the best platform to be building on for websites that stretch too far from a blog.

Shopify has a lot of traction right now, it's not something I've used but I believe you may run into limitations or at least not have as much control using a hosted platform.

Right now we're using Drupal Commerce. If you can find the right development agency it's a great technology for both the developer and the client.

Thanks
Ben.