I have a 280ZXT engine in my 240Z. I ordered a 1984-86 300ZXT coil and connected it to the standard 280ZXT triggering module.
The 300ZXT coil is supposed to be "hotter", and it did improve my overall engine response, however, I went from a standard 280ZXT coil that was in poor condition. I ordered the 300ZXT coil from Victoria British for around $50 - $60.
I'm using an MSD hi vibration coil in my car. I used a 510 coil bracket to mount the MSD coil since it's skinnier than the 280zxt one. I'm pretty happy with it. It cost about 40 bucks. My car is an 82 280zxt.