Drive 1000 mile bringing new old car back home
Can you trust the seller to tell you honestly if the car will make it? How long has he/she owned the car? What's the farthest they've ever driven it. Is there a parts store nearby?
I would ask these questions as well as bring some basic tools and parts. Do a quick evaluation before you set out and visit the parts store if you have to if anything looks questionable. Make sure to check ALL fluids, hoses, steering, electrical etc.
Being an "unknown" car this would be the bare minimum if it was me. Oh, and don't forget your cell phone & charger. Good luck!