I would say go for one here already landed. I bought a direct import, but if I had to do it all over again I would have bought one already landed that has receipts for work done. I'm saying this because I had to allow for $1,500 (excluding insurance & rego) just to get the car up to good running condition & for an insurance approved alarm. This meant things like all oils & fluids replaced with top quality stuff (coz for compliancing they put in cheap s%#*), alarm, new o2 sensor, NGK iridium spark plugs, tune with compression test etc etc. But not all Skyline owners are this fastidious. I made sure I did all maintenance on the car first to get it running like it should. Now I can look at cosmetic mods like rims, kits etc.
I own a series II and would recommend them over the series I as they are improved (as any incarnation) and look much nicer. My late 97' series II came with every factory option available bar body kit, which is the way I like it. I spent a good few months looking for the right one to come along too. I paid a bit more than most, but it's in extremely good condition in all aspects and I believe the condition of the car to be indicative of the kms on the odo. Happy hunting.