JL make subs that sound mellow and are nice to listen to. They produce 'nice' bass, if there is such a thing.
MTX's are what you buy if you want a sub to make you deaf. They are harsh and well, nasty.
As for their amps I do not have any experience with them. But, depending on what sub you buy, Jaycar make a couple of good amps that are around 1/2 the price of the leading brands and they work just as well.