In addition I must add that I found both my 33's on carsales (Have now bought 4 cars found on carsales.). Both well priced and very clean examples with documented history, so do look around as they are out there..
As for importing, well you might be able to save a few dollars or get a really nice example. However the delay in waiting and the potential hassle, for me, wouldn't be worth it unless buying a gtr. But by all means speak to an importer and see if there is anything on its way.
Don't be scared buying interstate either, just make sure you get it thoroughly checked out by a mechanic and an experienced/knowledgeable friend and do a revs check and run the numbers through the online checking tools. There's a thread here where you can get the vin put through FAST which will give you info.
Pretty much do some research, but beware that they are getting old and are typically given a hard life, and a lot of backyard mods, so expect the unexpected.
If you plan to track it and have some real fun, then i'd suggest trying to keep the other car just in case. Those walls can jump out at any time you know!! =)