Powerspark from eBay. £75 for the dizzy and leads. £17 for the coil.
I'm sure there are other ways to go but this is the way I have gone. Started the engine fine afterwards.. However decided to remove the carb afterwards to reseal it and the spacer broke so haven't set the timing or anything yet. Decided on a new carb as well so will update after I've renewed that and set everything up.
Norrie.