Kitchen tongs are about 23 cm and a barbecue is much hotter than a hob. Long tongs are not a luxury item, they are the difference between turning flatbreads over live coals and not doing it.
Length matters more than any other feature. Somewhere around 40 cm is the point where you can reach the far side of a grate without putting your forearm over the fire.
Get locking ones. A pair that will not close for storage takes up the space of a small pan and catches on everything in the box.
Steel rather than silicone-tipped for charcoal work: silicone has a temperature limit and glowing coals are past it. Silicone tips are fine on a gas hob and a liability over a fire.
Worth reading before you use them near enclosed space: carbon monoxide.