PowerPC vs. Intel

I was just about to get Adobe Premiere Pro on my G5, when I got an error message saying 'Support for CPU extension SSE2.' This error makes more sense in Windows, but it's basically saying I need an Intel chip? My question is where and how is the best place to get and to replace the PowerPC chip with an Intel Core 2 chip?

NOTE: I am not getting another computer, period. I just spent all of my money on the Production Creative Suite and I have no job to replenish it right now.