Best 7" tablet for 3D app

Hey there,

The company I work for develops 3D applications, usually online. We are doing a small run proof of concept Android app for a client of ours and we are looking for a 7" tablet to demonstrate the app on. Can people recommend the best model to buy?

Graphics capability is by far the most important feature.
It needs a decent amount of RAM
A good rear facing camera is a nice to have too
It must be around the 7" form factor

Ordinarily we would look to pick up a couple of Nvidia Shield tablets, as these are usually considered the most suitable for this type of thing.. but they seem to be unavailable right now

Any help is appreciated.