You could definitely use the pro option. You can sell up to 25 products and can have your three different options for each. The only thing you’ll be fighting, is the 3% transaction fee, which is a real bummer. Another option, is you can go to the ecommerce plan without having to use a specifically ecommerce template. The only reason I would advise that, is because there is no transaction fee on Weebly’s end and they have other handy tools like a shipping and tax calculator.
It really depends on how many prints you are anticipating selling and what their pricepoint is. If not very many and they are priced lower, the 3% transaction fee might not be a big deal. But, if you are selling them for $30 and up and sell a significant amount, that 3% transaction fee is going to get you pretty quick.
Hope that helps!