You don't need to use either. Get some McDonald's-type straws (ie fat, but not bendy) and cut them with scissors to exactly the height of the iced bottom tier. When you are ready to stack the cakes just push the straws through the bottom cake and they will support the next tier very nicely.
Three pieces of straw should do the job nicely, spaced out so that they are about 1" in from the edge of the upper tier's base.
It works well with sponge/Madeira type cakes. Skewers would not be reliable - being so thin they are less stable. So there would be a risk that, if you didn't put them in perfectly upright, the weight of the second cake could cause them to slide sideways and cut through the cake.