Where can I get a guitar tuner built?

Howdy,
I'm new here. I need to know where I would go about finding a source that would build guitar tuners for me in a particular size and shape. We build guitars and mandolins and are interested in the possibilty of imbedding the tuner in the head of the instruments. It would have to be smaller than normal to do this.

I would appreciate any thoughts.

Thanks,
Joseph