Your ICH10R I/O Controller Hub (ICH) chip has a maximum temperature, depending upon it's load and heat sink, of about 100C. On the three mother boards that I have that use this chip, they run at about 120F. Just curious, where do you see this chip spec'd at running at 75 - 80F?
I agree that at least part if not most of the temperature reading of your ICH10R is caused by its close proximity to your video card. Even with their usual configuration, with the bottom of the circuit board facing up and the fan and heat sink underneath, a fair amount of heat is radiated from the circuit board side of the video card.
Increased case ventilation will help in reducing this chips temperature, so if you can add fans to your case that should help. Depending on the heat sink used on the ICH10R, a tiny fan can be mounted on it, which will also reduce it's temperature. There are after-market chipset cooler heat sinks, some with fans, although mounting them is not simple and can be impossible. I've mounted fans to the disk drive cage to move air across the mother board, which I find helps to reduce both chipset and mother board temperatures.
Airflow or water cooling but I don't know if there's a wc block that will work on the SO2.
BTW, no X58 board from any manufacturer with ICH10R southbridge operates at 75-80 F, not even close. Every X58 board I've had, and I've had many, the sb operates at between 50-65 C and with multiple graphics cards they can get into the 70 C zone.