Pakdamek,
Take note of what Feezdya says about evaluating the car because that is probably the best mindset to have when one decides to buy a car produced a couple of decades ago. Forget about making sure if the engine is in good condition - its probably living on borrowed time. Don't worry about the suspension, bushes, etc - these are all wear and tear items and would need replacing anyway. The list of what needs to be replaced can at times seem daunting and probably not worth the hassle to most people but no one says it has to be done all at once.
Keep in mind that going from a Neo CPS to an R32 will require some patience. Not to say that the R32 is an unreliable car but be prepared for the air-conditioning to fail when you're stuck in rush-hour traffic or for your engine check light to come on suddenly just as you're rushing across town on an errand or for your HICAS to go bonkers just as you're driving to Petronas for an early morning GTJ run, etc. My point is that this isn't a new car and as long as you keep that in mind and prepare yourself for the transition from a newish car to an older one than all will be fine.
Don't walk away just because the car has been in an accident. Find out what sort of accident it was and how severe the damage was. If its just a panel which has subsequently been repaired or even replaced then by all means, go ahead. There are many Skylines around which have been in minor accidents yet none of them are any less sound mechanically nor compromised structurally. So fender benders, etc are nothing to worry about.
If everything checks out and you do find yourself the proud owner of an R32, then you have a few options - it's not all about the RB26. You must first decide how much power you want and can realistically handle and then consider the various options - keep the RB20, try something different in the form of an RB24 or even an RB25 which is much cheaper than an RB26 and more than capable of producing decent power. They all have their pros and cons from the lack of torque in the RB20 to the higher cost of the RB26 from road tax to parts and rebuild etc. That is a discussion for another day and one that deserves its own thread. Although I can't comment on the RB24 as I've only modified the RB20, RB25, RB26 and RB28.
BTW, the RB24 and RB28 are actually stroked up RB20 and RB26 engines. In fact, there are various companies offering stroker kits that can turn the RB26 into a 2.7 (e.g: JUN, Greddy), a 2.8 (e.g: TOMEI, HKS) or a 2.9 (e.g: Brian Crower). The RB24 if I'm not mistaken was something that emerged from the drift scene and there was the option of getting a TOMEI stroker kit or using stock RB26 parts to achieve the increase in displacement. It's definitely something along those lines but off the top of my head that's the best I can come up with. You could probably find out more with a little research.
That pretty much covers the range of performance Skyline engines used in the R32, R33 and R34 models from GTS to GTR plus what can be achieved using aftermarket parts. To the best of my knowledge, that's all the Skylines came with (hahahah cannot resist cucuk evidence based motoring but I speak only the truth LOL).
Anyway, sorry for the long post. You did say that you've never driven a Skyline so I have no idea on the extent of your knowledge. Regardless, every little bit of information helps and we all learn something new everyday.
To everyone else, well you guys should be used to my long posts by now. Plus, I'm bored and can't sleep.