i was also thinking that if he spent time saving, he might be able to manage 2 cars at the same time. and for the first few months of ownership of the skyline, just spend time going through it with a fine tooth comb. spend the huge chunk of change on the tune up, get the car on a lift and look at everything on the bottom(a PPI from a knowledgable technician mite be difficult), don't do any mods to it(maybe wheels). after all that, then begin driving it, just not daily, maybe every other day. don't listen to music, nor drive it hard, see if you hear anything out of the ordinary.
just because it's rare doesn't mean he shouldn't buy it. i looked an r32 b4 my stealth, only thing that detered me, the way it was imported(not sure if it was leagle), and NJ DMV didn't know what the hell i was talking about when i called em.
the only thing against the 240 and getting a swap, it'd be difficult to use it daily and do an engine swap. whereas getting something like the gtr, you just have to take care of it.
or check out the mitsubishi gto mr, quicker than a r32-33gtr, and just as nimlbe(mr=mitsu racing) rare, but other than tranny a standard gto tt is a parts car.
P.S. I'm a go after your dream kinda guy, not a person who settles.