The standard MAF can max out at anything from around 1 bar upwards ( 1.2 bar seems to be the norm ), depending on what kind of intake you have. Some people run 1.4 bar no problem, others only 1.0 bar.
You can't use a Z32 with a standard ECU only, as the signal it gives out is different from the standard AFM and the engine will run too rich. You need some kind of fuel controller to use one with the standard ECU, or a programmable ECU.