If you only want to use a bench hook for basic sawing, then one without refinements will fit the bill.
Left or right?
Make sure you get one that suits your leading hand – a right- or left-handed bench hook.
A reversible bench hook that suits your leading hand at both ends is most suitable as it can be turned around if one end becomes worn or damaged.
If more than one person will use the bench hook and they have different leading hands, then the best choice would be one that is both left- and right-handed at both ends.
Hardwood wears better
A hardwood bench hook, made from beech or oak, will wear better than softwood.
Plane truth about sub-bases
If you want to use the bench hook for planing, then a bench hook with a sub-base is best, as this provides protection for the workbench top when planing end grain with the plain on its side.
All of the above types of bench hook could be used for planing small workpieces along the grain and chiselling.
If you plan to cut mitres . . .
If you want to cut mitres and don’t have a mitre box or mitre saw, a bench hook with mitres cut into the stop would be useful.
Doing the back stroke
If you use saws that cut on the back stroke, a bench hook that has its stop set back from the front end of the base would be most suitable, as the wood to be cut can be placed on the far side of the stop,
You might need more than one
You may not find all of the the features you want in a single bench hook, so may need more than one, or perhaps a single bench hook and a mitre box or mitre saw.
You might want to keep one just for delicate work, so that you always have one with little or no damage.