Check two numbers before anything else
Every mount states a maximum screen size and a maximum weight capacity, and the screen must be inside both. Weight is the one people skip, and it is the one that matters: a large commercial panel is considerably heavier than a domestic TV of the same diagonal, and a bracket rated for a 75-inch consumer set may be nowhere near a 75-inch signage display. Take the weight from the manufacturer's spec sheet, not from the bracket's headline size.
Fixed, tilt, full-motion or motorised
A fixed mount holds the screen flat to the wall and is the cheapest, slimmest and most secure — right for a screen at eye level that nobody needs to move. Tilt angles the screen downward and is what you want for anything mounted high, above a reception desk or in a corridor, where a flat screen would reflect the ceiling lights straight back. Full-motion arms swing and rotate, useful in a meeting room where people sit off-axis, at the cost of depth when folded. Motorised mounts move under control and suit height-adjustable installations and accessible meeting spaces.
VESA, and the wall behind it
The VESA pattern is the hole spacing on the back of the screen — 200 x 200, 400 x 400, 600 x 400 and so on — and it must match the bracket or an adapter plate is needed. Just as important is what the bracket is fixing into. The supplied fixings generally assume solid masonry; stud partition, dot-and-dab plasterboard and glazed partitions all need different hardware, and on a heavy screen that is a structural question rather than a shopping one.
Brands
Neomounts, in wall, ceiling, floor and motorised mounts.
Trade pricing and business accounts are available for UK organisations, and bulk orders are welcome — request a quote.