inject code or redirect to another form with the product form that can pop up after you hit add to cart?

I'd like to add an image upload to the product form when you hit add to cart. I have tried to implement squarewebsites uploader but it only allows 10Mb and dev won't open it up more. I cannot seem to find an option that integrates in the same way with having the form pop up after adding product to cart. I am now trying to utilize Jotform but I cannot find a way to get it working with product form. I think Squarespace needs to have an option for an upload to a cloud service like google or dropbox for the commerce plan, having to utilize a third party for a form to get an upload button puts customer data at risk.