Symfony vs other frameworks for an eCommerce site

Currently, I am looking to switch from a home grown eCommerce website to a custom site using a framework. I need something that can upscale (handle hundreds to thousands of transactions), is easily maintained, and simple to customize.

I was recommended the symfony framework by an outside source, but I have not previously heard of it. My understanding is that using something like symfony would still require integrating magento (or its ilk) for commerce on the back end.

Is there a better solution? Is there another platform that would fulfill all of my needs?