OP, you're original post is still right with optical communication as well. Part of the problem lies within the fact that we don't know how much unseen light blocking dust is between here and there or other unfortunate large planet size non-radiating objects that we can't see. Something that lower frequency radio waves would not succumb to so easily.
My off the cuff guess is that you'd need to build a massive spaceship the size of an aircraft carrier if not more to generate the required power to transmit with the accompanying dish and electronics required. Try to get that into orbit affordably.