Having looked at hundreds of gimbals, I am going for cheap, light and simple. Essentially all versions of this are all very similar.

https://www.banggood.com/Light-2-Axis-Brushless-Gimbal-With-BGC3_0-Plug-and-Play-Stabilizer-For-GoPro-SJ-Hawkeye-DJI-Cheerson-p-1104837.html

To attach it, I will flatten a section of PVC pipe ( the piece that goes between the grips) drill and bolt in place.

The gyro unit that resides on the camera base may need to be re-oriented so that the phone/tablet can be attached to the (former) bottom of the gimbal frame. Pics will follow...