Okay, thanks for that.
I will like to work towards the budget of a 15k project car.
Making an assumption than you mean the S30 shape, you may wish to consider a LHD dry state US car. The most desirables are 240s but precisely because of that you can get a better body condition 280 for the same money.
A 2 by 2 260z (AKA 2+2) may well suit also but for many that’s a no no and for many that’s a great option for practicality and ferrying the family in it. But again, they tend to trade hands for less money than the 2 seaters.
Try to avoid a car with a sunroof - I won’t go into why as you can search the forum and find lots of info. Some love 'em some hate 'em but they can be a big hassle to close up if you don't want it.
A dry state car will have a better body than say a UK car but crispy / sun baked interior.
Be VERY realistic about your budget and expectations of the quality of finish you’re looking for. It can get VERY expensive VERY quickly and once you’re in you get sucked deeper!
Staying stock is always cheaper but these cars LOVE mods which really does improve them. For example you can get Koni adjustable shocks that just drop in with no mods but provide brilliant simple tunability for little outlay. Or you can go full coil overs that really enhance the handling etc but the limit is your budget!!!
Go see member cars local to you and / or go to events like Japfest, Silverstone, castle Combe etc and take a detailed look. No two Zs are ever the same and people have done fabulously interesting things like JohnyMD’s V8, JZ1 track day car, Ratsun ratty look etc or Richie’s pristine Red car or Toopey’s lovely 2+2.
Make a list of all the things you want to do to the car and parts you like, be honest with yourself and write a price next to each, then add 25% for unplanned stuff / change of plans (assuming you were honest with yourself on the previous task, if not, you can make that well over 50%). Then use that number to decide if you really want to go through the hassle of all that work or willing to add another say, £7-8k to your budget and start with a better car where you’ll have less rust etc to deal with.
Hope that rambling helps a little.
But tell us what you want to do with the project - restore to sell? Restore and keep? Resto mod with period or modern mods? Concourse stock trailer queen for shows? Track day car?