Daily driver I presume? No point spending on $80 oils. HPR5 will be fine. What sort of climate does your car live in? I would go with HPR10 (10W-50)
Note: This is a generalised explanation.
Lower the number the thinner it is (look up viscosity). The number before W is the 'cold' viscosity. E.g. 5W will be thinner than 15W. The number after the hyphen is the 'hot' viscosity. So a 5W-40 is thinner than 15W-50. For colder climates, you want a lower cold viscosity, e.g. 0W-40. For warmer climates, you want a slightly thicker oil (since there are higher atmospheic temperatures, the oil will heat up quicker and run hotter). So, for exampe, if you live in Cairns, you would use a 10W-50 oil, in Tasmania, same engine, use 5W-40. How new the engine is (tolerances between bearings, rings, etc.) is also a factor. If you put 0W-30 oil into a 100+k km/20 years old engine, it'll burn it because the oil is so thin it seeps past rings etc. But if your engine is a fresh rebuilt, or you have a new car, you can run thinner oil because of the tighter tolerances.
Thinner oil = better flowing = less loss (due to lower flow resistance).
Thicker oil = better protecting in higher temps or for older engines.
The difference between the two numbers also is an indicator of its stability. E.g. 10W-30 is a lot more stable than 5W-60, but the operating temperature range is also a low narrower. If you lived in a cold country (e.g. Scandanavian), you would be using 0W-30 on a relatively new engine because it's fricken cold outside.
So, factors include: operating temperature range, engine design, how worn the engine is. For a non-turbo NEO engine, I would use 5W-40 (HPR5). Note that you can use oil with a 5W to 15W cold and 30 to 50 hot viscosity. The RB engines are designed to use oil in that range. Remember that the Penrite range has "extra 10", so e.g. their HPR5 is actually 5W-30 oil with additives to increase the hot viscosity up to 40.
I recommend Penrite because it's Australian. You are free to use any semi-syn or full-syn oil. If you notice that your car is using a bit of oil, change to a higher viscosity (e.g. from 5W-40 to 10W-50). Remember to use engine flush when changing oil brands/types/viscosity.
For reference, Nissan 200SX oil is 7.5W-30 (what was used in you car when it was new).