Hey buddy, I was also researching into putting an RB26 into a 350z over in the states, I'm moving there fairly soon and wanted a ride. But in researching, I found that it's difficult to put the RB into anything that's LHD as the turbo and ancillaries are going to interfere with the steering components, unless you spend copious amounts of money into putting a high mount single turbo onto the RB.
RB26 into 350Z
That's just an example, be it a drag car, but thought you might like a link of how it can be done.
It can be done, but it's a big cost hit, compared with rebuilding a VQ series engine. I'm sure you've come across the U.S. sites which do sell the RB's like I have, which is why your looking at shipping from overseas direct. Perhaps wait for how the new VQ35HR engines are like? but im unsure how it's going to be be boost-friendly as it has a higher compression than current VQ35DE's.