Basically, I need to be able to place blocks with their own set materials via a materials button (UMG) that works with static meshes because I can use “Set Material”. With ISM, all of the instances can only have 1 material for the whole component. At least that is what I have found and what people have told me. I need the player to have control over each block individually. I am looking at voxels as the answer, plus it would be wonderful for my game 
So I just need to know especially (I should have stated this in the original question)where to start on voxel data so I could implement voxels into my game.