Personalised bombs? As for now - possible, but just "somehow".
Only thing you can do is changing the default textures, which will (obviously) change texture for every bomb that uses it.
But if you do for example FAB500 and FAB500_B which will use different mesh and texture than others you are step closer. But then you will need to make special loadout that will use that bomb. It may even work online - with different loadouts. But it has a catch - even if you manage to put there two planes with different classfiles (that can make serious bugs) and even if your (or the other one's) game is able to read that bomb without having the files for that bomb, you will need to use specific name for that bomb, because if the other one uses bomb with the same name, you will not see his bomb but the bomb
you made. If that makes sense.
Cheers,
your dreamdestroyer