You're looking for an AIO (all in one) but also with a touchscreen... Those mounts are standard anyway.. Not THE most common thing at a best buy but they're out there.. At the hospitals we use Dells primarily..
Here's a newer one AIO + touch, slightly bigger than your current one:
https://www.dell.com/en-us/shop/desktop-computers/inspiron-27-all-in-one/spd/inspiron-27-7710-aio/na7710fioms
Other brands have it, just search AIO and touch screen, and make sure touch screen is picked as an option when ordering... You could possibly also go with a surface tablet, that's also touch (obviously since it's a tablet) but I am not sure how big they make them (likely not as big as you can get a PC, like 27") nor do I know if they have a backside mount. HTH