Drifting isnt about being different... The only reason said cars are more popular is they are piss easy to work on and theres a gazillion parts out there for them.
The only flaw imo with 300 is the engine bay space. If you where going to use it for drifting/racing you could lose a lot of weight by stripping it and fibre glassed panels etc.
Also the overheating problem would be easily addressed.
I cant remember what parts but there is interchangeable from other nissan that fit 300's, might be good to check out some 300zx forums.
If I was going to use one for track one of the first power mods Id be doing would be to convert it to single turbo, will free up a bit of space and reduce engine bay temperatures slightly.