I suspect what he means is
[And, this is what I would do] --
a) Use the Morrowind Construction Set to open that mod, as the "Active" mod. [Anything that mod adds will then have an "asterisk" attached in the CS].
But, also load up "Better Bodies," along with MW, Trib, Bloodmoon, or whatever else that mod requires/is dependent on;
b - Pick a cell like "Todds Test" or something, and put copies of the two "Shady Smuggler" NPCs into it.
c) Go find them in that cell, in the Render Window, and equip them with your new armor (one is male, the other female, so you can see what it will look like on both, provided it has both male and female versions).
Since you already have "Better Bodies" loaded in addition, you can see what the armor would look like on a BB NPC or Character.
d) Obviously, DON'T SAVE the mod .esp after all this manipulation. Better yet, do your investigation on a copy. Then you can do the quest you mentioned to actually get the armor, once you are satisfied it will work for you.
DARoot