Check this out.
Now that the PFC for the RB is discontinued, Haltech has released a direct replacement ecu for the R32/R33 Engines / Cars. You can use the OEM MAF(S) or upgrade to MAP with this ecu, its really your choice.
Here is a link to haltech's site about it:
Platinum Pro R32 / R33 Plug-in - Haltech Engine Management Systems
MSRP Is about $1680