If you go to the parts store in the help section I bet you can find the $5 kit locally. Try that, if it doesn't fit then order the MSD one.
They come with heavy springs, MSD manual for that dizzy says 22 degrees by 4000 RPM, not too bad, but I would want it all in by 3000 RPM.
I would use all light, 427 uses one light and one medium, either will work just fine. But whatever you use, make sure you set the timing after it stops rising, meaning, slowly rev it with the light on until it stops advancing, then set it at 36 or so. Don't just set it at 3000 and assume it stopped rising, or it may rise too high in the upper RPM. I also like to know at what RPM it stopped rising, use your tachometer or buy a timing light with a built in tach so you can do it all from the engine bay.
If you don't have an advance timing light, then make another paint mark on the balancer at 36 and set it on that with vacuum advance disconnected and revved up until it stops advancing.