The amethyst looks like a copy of the Megajolt Lite Jr, except it cant control a edis ignition and has less features.
I would go for the Megajolt Lite Jr , witch is cheaper to start (+/- $175,- in the states) with and has more features and is for edis, witch is rock solid system. And if you don't want a edis ignition, you can go for a MSD 6 BTM, witch accept point, hall or vr sensors, and is adjustable by turning a knob.