I have an old set of RED tuning vices, from maybe about eight years ago. They attach to a table and hold the board both flat and on its side. I've been very happy with them.
They're fine, except for the fact that the non-slip rubber degrades over time - to the point where the red colour of it bleeds into whatever porous surface it touches. I discovered this when I found reversed RED logos permanently embedded in the white base of a brand new board - nasty, impossible to remove, red blotches. NOT happy!!!