If you're a start-up and looking for a MVP especially in an eCommerce vertical market, we'd love to be involved.
We'd stress eCommerce as `partnership` because building and running a high-end on-line store is a journey and not a quick out of the box product. Your actual shop or its foundation won't take long to set-up, but if all you want is a vanilla store then just choose 'Shopify'.
We'd suggest a custom PHP system, e.g. OpenCart [in extremis Magento]. There is a reason the World's top e-Commerce sites choose these platforms and while we can have a pre-installed template for you very quickly, its development is an investment and is truly bespoke or we'll make it that way.
You start with a theme [or maybe blank] and then overlay on this, which is all done with custom PHP/HTML/CSS/JS. There will be a powerful backend CMS and this is great for maintaining products, but we're talking about the workflow of the site and one which is unique to you. This is where a professional Web Developer is required and not just a Web CMS Manager. You need both, of course, and the latter is probably you. We can also customise the back-end in extreme cases, but that's unlikely unless you are a huge eRetailer.
In light of some technical developments [improvements and the contrary] we are only taking on new projects with OpenCart.
Our relationship with Magento has alas come to an end as their systems are just proving to be unworkable on a cost-management basis for clients.