Don't worry,buy the dualcore above 2.4Gb (around 100-250$),download "CPUZ" to check your mainboard (can support dualcore or not)
get an intel between E7600 to E8600....
then nowadays emulators are no problem for you... your graphics card is enough for emulating dolphin or PCSX2 and they are easy to overlock...
it is the best thing you could do. with your current CPU you dont even have a chance to get about half of the FPS