It may be time to invest in that i7 rig you've always wanted for emulation? That's going to cost you about the price of 1000 used PS2s/Wiis.
I don't get people who'd upgrade only for emulation. I upgraded a few years ago because it was long overdue and I play games on PC. My PC just happened to be powerful enough for emulation, it's not like that was the original goal.