Here's the suspension/wheel/tire setup of my STS 99RS:
KYB AGX struts
Whiteline sway bars (22f/18-22r set on 22)
STi upper mounts
Whiteline strut braces
Subaru 15x6 alloys
195/50-15 Bridgestone Potenza S-03 PPs
With that setup, I've been running 40psi cold (at all four corners). Different size wheels or tires or a different suspension setup will change that of course (especially if you don't have swaybars or adj. struts to change your oversteer/understeer bias).
my setup is similar to yours warp3 except that my sway bar is 18mm and i have 16X7 wheels on s03s.
i just need a baseline tire pressure to start with. my AGX are normally set at 3f/7r depending on the autoX course. i've experimented with various tire pressures and it seems there isn't much difference. I might lower my rear pressure to 36psi and leave front at 40psi to get some oversteer action.