I have a low mileage 2003 JDM and very pleased with it - I am the second UK owner, The post linked above is pretty thorough - Spec's on the JDM can differ as I recall most UK standard bits are optional extras on the early Z33 Fairlady- like Brembo brakes for example.
I have have swapped my centre gauges for UK spec as I wanted the running info in miles not km's, the satnav is all Japanese and did consider popping in an old XTrail unit but the cost (£250ish plus fitting and doesnt do postcodes ) versus what you can get get a Garmin for means its was really not required.
I must admit I prefer the rear box number plate recess and having a few buttons in Japanese in the car just gives it a bit of character. No issues at with servicing and modding. Resale on imports vs UK spec isn't that different now but read the forum guides - ask questions, but essentially they are very similar so all down to personal taste. Whichever one you get, as long as have done your homework to decide a Zed is for you - you will not be disappointed and join the rest of us with fixed grins on our faces everytime we start the engine or look back in the carpark and think - thats mine ! Beware Zeditus
Right..... time to pop a flare