upload more than one file per product with Personalization

Hi,
i have a product at https://www.cushypaws-pet.co.uk/products-page/cushions/personalised-handmade-cushion/

i have added personalisation to it so you can add a name but also need the customer to send me as many images of the pet as possible to create the product.

at the moment i can only select one file and upload.
i either need the ability to hold down control when selecting or multiple upload buttons

is this possible?

https://www.ads-software.com/plugins/wp-e-commerce/