This is issue is pretty much a dead horse now but I'm sure there has to be some sort of solution. I have 2 ideas of how this can be addressed.
1. Multiple equips in one line: This is pretty straightforward, though I'm not sure if the system in place can handle multiple actions in a single line. It would look something like this: /equip head "piece" body "piece" ear1 "piece" feet "piece"
The part names could also be abbreviated to allow more stuff to fit in a single line; i.e. number the boxes 1-16.
2. A separate menu: This idea is to, like macros, give us a book of equips. This is already done for job changing, so why not give us some extra control over it? You could name each equipment set and then in your macro just type: /equip "TP Gear"
That way you could change all 16 pieces in a single line.