I have an iMac 8,1 which still has a huge amount of use left in it but it's got to the point now where in order to make the most out of it, it needs an upgrade. It's running 10.5.8 but apparently in order to upgrade it, I need to first make sure it has Snow Leopard on it. I can't find anywhere to purchase a 10.6 disc from and finding downloads online is drawing a blank too. I want to get it up to at least Mavericks. So... what do I do?