Are you planning on a full restoration? Do you "want" to or "would you like" to do this. It is hard to tell from the voice of the verbs in your first sentence.
If you will be doing a full tear-down and build-up, you can go much farther in upgrades.
The most important things for reliability are the 11 blade fan, getting rid of the thermal reactor exhaust, and adding a "pop-off valve" for the CIS airbox. Then go through and refresh the brake lines and fluid, shifter bushings, etc. These are easy things for reliablity/safety.
Performance-wise, the stock brakes are good already. Engine, there is not much you can do while keeping CIS. Carburetors opens the door for new cams, valves, rods, pistons, etc for higher compression and higher revs so more power.
