What's more, I have no use for just a chest piece. Sell me the whole set!
In point of fact.. you can mix other pieces of gear freely with the chest piece to come up with unique looks. No reason to be boxed in by using a full set pre-configured for you by Bioware.
The chest piece is the key part of a gear set from a looks standpoint, in all but a few cases.
Experiment, be more imaginative IMO.