If four satellites is all you want and they are all close enough together to use one dish, there is no contest, four LNBs and a switch are the answer. If you feel you may ultimately want to do a bit of roaming, or you require say 28.2, 19.2, 13, 1W and 30W, then a motor is the only option.
I've often thought that a novel way to receive several satellites would be to mount several dishes on one pole vertically, largest diameter at the bottom. That way you would maximise the signal available from each satellite.Of course it would add to the expense of extra dishes (but they are not that expensive these days) and the pole would have to be fairly tall,(and sturdy) but otherwise it should help in being able to receive marginal signals for a certain dish size requirement. Also if you wanted to change one of the satellite positions you could achieve this without too much difficulty.It will also make a good talking point in the garden.