It would be better to do that on your terms than being forced to by a hardware failure coupled with inability to quickly locate replacement hardware.
Sooner or later, you're going to have to find a way to upgrade to more recent hardware and a more recent system.
This is one major hazard of remaining reliant on such an old system: sooner or later, you're going to have to replace your hardware, and there's a dwindling supply of used hardware found in places like eBay that is capable of running 10.6.8. On a system old enough to be capable of running 10.6.8, this very well could be a hardware failure. Very few Mac threats involve kernel extensions. None of these are likely to be caused by any kind of Mac threat. These are generally caused by one of three things: bad third-party software (specifically, software that installs a kernel extension), a badly-corrupt system or bad hardware. I notice that the screenshot you've provided indicates that the machine is suffering from kernel panics. I believe that ClamXav will scan 10.6.8 fairly well, but it is no longer free. I don't know of anything that is both free and that will do a remotely decent job of scanning 10.6.8, unfortunately. We don't have anything that scans 10.6.8.
