I've fitted a Accuspark conversion kit to my Dizzy and been very impressed. Works well, and good price. The previous SimonBBC one failed very quickly.
Your dizzy could be FoMoCo, Lucas or Bosch.
I'm using a Bosch Red Coil (Ballast), with an Accuspark Ballast Resisitor. However you can fit a Non Ballast Coil, and bypass the resister.
Bosch RedAccusparkI'd go for new plugs, leads, Dizzy Cap, rotor arm if you've not already done so.