Acrylic Display Case Triangle Connector Assemble Clear Display Box Corner Joint Transparent Plastic Showcase Hardware Small Parts with Screws 8Pcs

Specifically prebuilt for that? Unfortunately, no. I know Rolife has some bigger ones though. And like I said acrylic really isn’t super tough to cut. They just need a straight edge and a box cutter and preferably a clamp and then I find these corner guides really help you even see them on some of the kids.

They are not easy, but if you do, I recommend using these