Pretty sure any conventional external cup threadless headset will work. Believe the '97 fork had a 1 1/8" steer tube. Assume that you have the fork and can verify.
I was mistaken about the 1989 frames. I was thinking they had the original style dropouts. 1989 was the first year for the cantilever dropouts (I was thinking 1990), so would look noticeably different from your 1986.
I don't have a hard copy of the 1986 catalog but you can download it here:
https://vintagecannondale.com/catalog/
Rustoleum coral looks pretty close...
Swept back bars like Rick posted in the 2nd photo will get your hands farther back which will result in you riding in a more upright position. I would guess that there is a swept back bar out there that your shifters will mount on.