H165 are getting rare but available centre from some bluebirds.
Gav there are many h190 in vanettes, urvan, 720 utes, navarras and
some other nissans its essentially a 10 bolt diff whereas the h145,
150 and 165 are supposedly all 8.
The h150 is common in 120ys and with some mods can be as mentioned
fit in a h145 housing. The benefit is when using a cheap lockup unit
like the phamtom grip knock-off its supposedly strong enough for
decent power providing not abused for burnouts etc.
The h190 is the one I would go for abuse.