I'm having random freezes, and process of elimination is bringing me to my 7 year old PSU...
What elimination have you already done? Have you already tried with another PSU to prove that the old PSU is at fault? I just always get concerned about buying something to fix a potential issue and then finding that the fault isn't fixed. Normally a PSU would not give you random freezes as it would instead freeze when power steps up which would be systematic. You could use Speedfan to log your voltages, temps, and CPU load and review after there is a freeze to see if any pattern emerges. With systems since the Pentium 4 the bulk of system power is delivered by a 12V connector to the motherboard and it is the motherboard that steps it down for the CPU and other motherboard components. It is therefore unusual for a power supply voltage to cause lockups with modern systems, the motherboard VRMs handle it.
I second the G-360 if you do have to replace your PSU.