If you mean, which op amp should you choose, I suspect it's the one with the highest GBW, but that might be overkill. Does Pspice have a parameterized behavioral op amp model? LTSpice has UniversalOpAmp2, a 2-pole model, with the following tweaks:
Avol=1Meg GBW=10Meg Slew=10Meg
ilimit=25m rail=0 Vos=0 phimargin=45
en=0 enk=0 in=0 ink=0 Rin=500Meg
These are the default values, and all can be changed. Some of these are self-explanatory. All are described in the online manual.
This part can be very handy, and it generally simulates faster that a manufacturer's model. You can switch to a mfr's model after you find the values of the parameters that are important to you.
Pspice probably has a similar part.