This thread needs a serious update to the OP. It makes megasquirts look daunting to work with, and they are not.
You do NOT need to change your stock ignition setup. Stock works fine. An assembled Megasquirt-II unit (v3.57 board) will work right out of the box with just a few things that are required for any setup. (tachselect input, tachout, adjusting potentiometers). There is also Microsquirt. As a matter of fact I recommend it instead of the MS-II. There are more options out there that work better than the original megasquirt boards (MS-2 based clones that DIY does not want you to buy because it takes away from their sales, even though they're hardly "clones" and moreso improved versions with better hardware, VR sensor conditioners and pre-installed 4-bar map sensors)
However for the person that would rather NOT mess with an ECU's internals I would recommend using a Microsquirt for a budget solution, or a Megasquirt-3X or Pro for easier installation (you will still need to do some internal tinkering on a MS3X, but it will be far easier to wire up)
As of today, Megasquirt II and III does not like to use the stock ignition setup as-is, so you WILL need to modify that for it to work, I might make a detailed how-to on that later on if there is enough interest. However, you DO NOT NEED to spend ridiculous money on a crank/cam trigger setup to GET IT TO WORK. With that said, I DO recommend getting a crank/cam trigger setup INSTEAD because of various reasons, mainly that the megasquirt can default into crank trigger-only mode if the cam sensor fails (it soaks in heat the most) whereas the stock ignition's VR sensor might fail and leave you stranded.
Also, the stock ignition can't seal for shit, it always freaking leaks oil so there's that.
With that said, you WILL want to setup wasted-spark ignition once you do the currently-required mod to your ignition, as you will no longer be able to use your distributor to,well, distribute spark (you can, but it's much easier to change to a wasted-spark setup)
The beauty of Megasquirt is that you can use pretty much anything anywhere on the engine, so you can get any kind of wasted-spark coil, coil on plug, etc. that fits the engine the way you want it to and get it running with that. You CAN run full sequential ignition and injection on a MS-II but it requires enthusiast-level ECU soldering skills and circuit knowledge.
You can only run sequential IGNITION on a Microsquirt, it only has two injector drivers so you're stuck to, at best, semi-sequential injection (timed batch fire).
There's much more info to be given here but the point to take away from my post is, this OP is wrong and extremely outdated and spreads misinformation TODAY. It used to be relevant and accurate many years ago. It no longer is.