I have an old pc with a Gigabyte GA-B75M-D2V pci express 3.0 rev1 micro ATX motherboard, PSU is Thermaltake TT500NL1Nh-1 (500w) and existing CPU is an i3-3220. Could anyone offer some advice on upgrading to a better CPU and adding a graphics card. I'd like to use this pc for basic camtasia video...