Build an Online Store

I sell custom spiritwear(high school) t-shirt designs. I need a multi function site that allows users to shop all of the designs. After they find a design they like they need to be able to update the wording, as well as colors, and mascot. This should be done so they can see the change live. They will then need to be able to select the garment type the would like their design on. This needs to be a fully custom built solution. I am not looking for a software that can be made to fit.