Well, I use Ecwid as my shopping cart, and one of the things available under their Silver plan, is the ability to have Options per product. For example, I have gift certificates:
https://kaelindesign.com/pendants/#ecwid:category=377490&mode=product&product=1615620
And with the different options my customers pick, the image changes. You can set it up with multiple options, so that for me, I could have a custom ring listing where the stone could change, and the metal, with the price changing accordingly. I have one of my rings setup with different metal options, but the same picture here:
https://kaelindesign.com/rings/#ecwid:category=377491&mode=product&product=5334493
The neat thing is, that this shopping cart is very very flexible and easy to install. Learning to tweak it is dead easy, and they’re improving it all the time.
You’d have to have a picture for each option change, but it’d be a way to custom build an order. Would that work for you guys?