The N 95 should be more than adequate. It is not the individual virus that is airborne, but rather virii in a droplet of secretions. All droplets of secretions should be a good deal larger than 0.3 microns.
Meanwhile the doctors that have been working over in Liberia and the other affected countries that followed the protocols and have seen their fellow doctors still contract Ebola and die from it have no idea how they got it.