I know I can go to a special equipment purchase screen through a hero and that is really cool. This suggestion is for when you are in the general equipment purchase screen.
when I tap on an item to see it, it would be nice if to the left is showed a list of my heroes that could use that type of equipment. Grey out the people who couldn’t use it right now (too low level or whatever). Then show a green up arrow next to each name if it would be an improvement or a red down arrow if it would be worse and a grey equal sign if it is the same or equivalent.