Your mention of AWR makes me think this is a RF amplifier.
So your OP and device attributes will be determined by more
than quiescent current and max Pout. You will also (presumably)
care about things like distortion / intercept points which means
keeping the gain and load devices quite linear, and BW which
wants you to run smaller devices, hotter (conflicting with some
of the other care-abouts while helping others).
I think in the end you'll be finding your way through this
multi-walled box by a battery of simulations to optimize.
You might begin with determining which of the Class-es
is most appropriate to your application (modulation schemes
tend to push hard, on this, and new modulation schemes
that enable use of crappy cheap devices are always sought,
and turned into standards).
No mention of Class C, E, F which are more "switching"
RF PA styles (w/ substantial effort in the match / transform).