is 240z good for drifting? Ney, its good for restorations and storage in a nice cool dry garage! lol
Its going to be hard to find an s30 out there set up for drifting (as for inspiration) but even when you do its not going to be as good as any S-chassis. I mean the s30 chassis is strong for a car from the 70's but its still soft, but going with a 280z even an s130 wouldn't be too bad of an idea because the 280z had many new chassis reinforcements compared to the 240z and 260z. And the 280zx was a completely different car with much stronger chassis.
http://www.youtube.com/watch?v=8g5eIVMfuas and if you surf youtube you will find many more 280zx drifting videos A) because its stiffer than the s30 and B) because zx's are crap and you can thrash them without feeling bad lol.
But as for engines forget the carbs and go with an L28et or go bastard with any V8.