As far as I can tell, and I'm very new, so I may well be wrong.
There is no "high" or "low" air pressure bottle, the high and low is referring to the regulator that you attach to your air bottle.
If you require high pressure, you need a high pressure regulator and an attaching bottle.
The ratings on the bottle are for the maximum pressure the bottle can contain so the higher the PSI rating, the more air it can store for the same volume, but your regulator controls the output.
Or, I'm totally wrong, in which case, ignore me.