I'm with Captain Rick on this one. rent them on scene, or just understand: if you are going to become a serious traveller to dive destinations, you might want to get a bit more flexible and adapt your system to accept hard weights, at least for travel configurations.
Soft padded neoprene weight belt pockets can be a viable alternative if skin bruising is the issue.
Obviously, the TSA could care less about your "shrapnel" concerns. Even those dunderheads understand that it is an inert metal. Put it in carry-on? Not if you are a serious dive traveller. Carry on weight is limited and once your destinations become more involved, you are not going to want personal control over that extra weight. Ugh.
Many resorts and liveaboards have soft weight as a standard or an option. I frequent one resort that rents them out, but if you schlepp some down with you to add to the pile, your rental is free. Contact the resort or dive shop on premises and inquire.
Best advice, again- adapt your system to what is commonly available.... or face the baggage weight limits when you start thinking about other dive gear.... cameras, video, all the toys!