Digital
Build a cheap flexible touch-screen interactive.
We've done so much, with so little, for so long, we can now do anything with nothing (well getting close anyway)
Making the digital part of digital interactives is getting easier and more accessible every day, getting them on gallery though is a different challenge, the hardware is expensive or proprietary or only works with one predetermined program (unless you've got the knowhow and guts to fundementally alter them), or you need a full digital team.
On a related note...
Did you know Raspberry Pis are awesome. Raspberry Pis are awesome and over the last couple of years they have only been getting better. Like they can even run a 4K touchscreen monitor straight out of the box... you see where I'm going with this?
There are a few things you're looking for when you think of on gallery interactive: