A lot of people have been asking for cloak and others have been against it. I offer this as a suggestion, take the original Briar Patch in OB in terms of difficulty, amp it up a few levels. Apply it to a stealth mission in infiltrating a Klingon Prototype shipyard under a time limit. Make it next to impossible, the reward is a ship device that can be used for a cloak and access to skills revolving around it.
It's an interesting idea but as the above poster said any kind of item that gives a serious boost to a player will become standard for PvP combat at thus everyone MUST have it. If you don't have it, you'll have a serious disadvantage.