I have 2 self printed vats, One based on the thingiverse design and another I modified. Both have been in use for a more than a few weeks and perform as well as an original vat.
I was worried about leaks but have not had a leak so far (knock on wood ). I used an acrylic bottom in case something went wrong, I didn’t want to break a glass bottom. A 12" square will make 4 vat bottoms. I scored and snapped it into quarters. I used the clear color from this page.
The print just fit my XYZ DaVinci bed. Printed in PLA. One vat I sealed the acrylic bottom with silicone adhesive and the other with a 2 part Devcon plastic weld epoxy. PDMS lined as usual. Both adhesives worked fine, the epoxy sets faster.
If you have the means to print one on a FFF printer, you might make it yourself. YMMV.