A directional antenna will definitely maximize range. You can make a yagi or helical antenna or buy a large patch antenna and that will probably be good enough for many if you have it pointed at your transmitter with sufficient power. As long as it's not horribly cheap, video receivers make less of a difference for strict through-the-air long range than antennas do.

Your transmitter antenna should be a high quality omni antenna. The TrueRC OCP, Luminier Axii, and various VAS products are all considered very trustworthy for this purpose.

Ideally you'd want a ground station that tracks a directional antenna onto your reciever with a gimbal, but failing that most directional antennas have a fairly broad recieving range and you can just put it on a tripod and point it that way.