Not much cheaper than the distributor setup. If I go carb, I'm leaning towards the arrow racing setup. Looks really cool and makes the engine look like it was meant to be there.
You dont need all that. Just the controller and wiring harness. A distributor is a step backwards. Plus you dont get to take advantage of the dual plug with the distributor.
Timing is adjusted using free MSD Pro data software on a Laptop. Very easy to create timing maps and transfer them to & from the laptop to the MSD Controller.
Not sure what you mean about mixtures of different parts.