I have heard that the new Plasma box works quite well. I'm not sure how the MSD DIS4 would work with the stock EECV because the coils receive the signal directly from the ECU. I have been using the MSD DIS4 for over a year on my 99 GT, but I have an Accel Gen VII EMS which can control just about anything you add.
well I'm in the middle of building the wiring harness to make it run properly without the mass amount of splicing that seems to be required.
I already have a plasma booster on my engine, and it works well, but I'm going to the DIS4 setup for the two step, and the rev limiter, definitely need to get rid of the stock rev limiter with my combo