The Stovebolt Site Forums The Shop Area Engine Shop Mallory, Pertronix, Langdon or??

Below is the extent of my research so I am hoping now for good solid honest opinions on what HEI Distributor to buy. How does the vac advance work on these? How is fuel economy? Mostly, how is performance affected?

http://www.langdonsstovebolt.com/store/#!/~/product/id=1222040

http://mallory-ignition.com/dist-chev-6cyl-235-unil.html

http://www.pertronix.com/prod/ig/flame/dist/cast/default.aspx

There was also a Bolter who had a how-to (Jason) here:

http://www.greasygringo.com/2012/06/59-chevy-hei-conversion/ and when I pressed him a little on parts..

Here is the parts list:

Standard Motor Products LX105 Ignition Reluctor $1.50
Standard Motor Products LX103 Distributor Ignition Pickup $12.59
Speedway Motors 91012338 Stock HEI Replacement Module $14.99
AC Delco 10474610 HEI Module Heat Sink $12.73

Any words of wisdom on where to go from here? Thanks!