I know exactly what you're going through. That has been my issue the last couple of months. Mine has 220k on it and things are starting to fail as it is also my dd. I have decided, however, instead of spending money on a new car, which I probably won't enjoy as much as the Z, my baby will be going to a restoration shop in the next week or so. Hopefully I will know later this year if I made the right choice. I am looking forward to the end result. Good luck with whatever you choose.
Previous Z's-- 1990 Aztec Red 300ZXTT 1984 Limited Edition 300ZX Turbo 1982 Medium Blue Metallic 280ZX