Who are you buying the tools for and for what purpose are they to be used? A tool box is not a tool bag? Was there a specific request for a tool box?
If this is for industrial work they may in fact want a tool box. The good thing about a tool box is that you can lock that sucker up and even chain it to a column or lift. You get a lot of money invested in tools after awhile and don't want anyone walking off with them. A bag can be cut loose with a pocket knife.
Good advice growler. If management wants a "certain size toolbox" they may; want to see if the guy can follow orders, help him/her protect their investment or in some cases "they" furnish tools that won't fit inside of the "box"
If "they" give you a list of tools it may mean "they" will replace the contents and only the contents, that appear on their list, if the "box" has been broken into (or worn out thru normal use).
Got to watch "them" they can be devious.