1. No reason you can't run black coils, with the red box, but it is better to run the red ones, as the resistance is different and you will eventually burn up the black coils with the red box.
2. Are the black boxes better? depends on who you ask, but as to the one with the vacuum and the one without, you definitly want the one with it. These are the FJ boxes, the ones with out are the XJR boxes. Differeance being the XJR box has a 9500 rev limiter and the fj has about a 10200 limiter.
3. Yes. Blue plate is better asyou can adjust the ignition timing easily.
I much prefer te red box system, but the FJ box setup is just about as good.
I would say just buy the extra pickup and run it with the black coils (if for temp use) but if permenant, get a second set of red coils as well.
Also, when you install the blue plate, be sure to use a 15 thousandths feelerguage and have tat least that clearance between the pick up and the rotor, or it will eventually rub and ruin the pickup