I'll start by saying that I have never been one for penetration wreck dives, so I may be missing something here myself, but is there a reason why you think the answer to this question is different for wreck diving than it would be for any other kind of diving?
If you are referring to the lift capacity of your BC, I don't know what there is about "wreck diving" in particular that would tell you whether 16kg is just right, too much, or not enough - or at least nothing special about wreck diving that would outweigh the importance of other weight and lift issues that apply to other kinds of diving.
The questions that tell you whether 16kg is the right amount of lift depend on you and your equipment - your body, the weight and buoyancy of your tank(s) full and empty, the buoyancy of your exposure suit, and the weight of whatever else you're diving with, etc. - the same questions that you would ask whether you were wreck diving or doing something else. If you're planning to carry any equipment that you would not carry for some other kind of diving, you need to know what it is and what it weighs (at or near the surface and at the depths you plan to dive, if different) before you can figure out how much lift you might need to manage it in the water. And if you carry any extra weight for "wreck diving" stuff, you should be able to leave behind other weight that you would otherwise need, so that you end up in the same place - neutral at the safety stop at the end of your dive with your BC empty.
If you're talking about deep and prolonged diving with double tanks and stages and the like, you really need to get specialized training and learn the answer to this question there, because there's a lot more to that kind of diving than figuring out the amount of lift required to get all of that stuff (and you) back to the surface.