That's a huge chunk of money that can be spent elsewhere, and the engine will run just fine off a basic electronic upgraded distributor.
The engine will run just fine off properly setup points as well.
Here are some 'points' about each.
The difference between Pertronix($80) and the Summit CDI($130) is 50 bucks.
What you get with points eliminator:
1. Convience. You never have to change points.
What you get with CDI box:
1. Multiple spark discharge below 3000 RPM. Insures complete combustion.
2. 300-500 volt discharge into the coil primary creating a hotter spark on the secondary of any coil, even a lowly stock one. This allows you to open up the plug gap, even with a stock coil.
3. If you use points then dwell becomes irrelevant. Points will last for years because they are no longer switching high current into the coil primary. Its the high current that eats points. With a CDI box they are just switching a low current 'control signal' to the CDI box.
4. Not a big deal but they do provide a clean Tachometer output line.
For the above reasons a CDI box will make starting easier and smooths out idle, might even improve gas mileage a bit.
Points eliminator only replaces points, thats all. For the 50 bucks difference I would take the the CDI box.