I need help computer shopping! Which is a better idea?

I do a lot of memory intensive multitasking. . . mainly for music production, recording, and live performing. . . including reFX Nexus, FL Studio, and Sound Forge. I need something fast, since my computer can not handle its demands. (yes i have tried EVERYTHING from reformatting, to latency settings, to asio sound drivers, to buffer lengths). Which is the better way to go, and is there really much of a speed difference?

- AMD Phenom X4 2. 4 Ghz 16GB DDR2 ram
- AMD Phenom II X4 2. 6 Ghz 8GB DDR3 ram

The 2nd one has faster processing and the ram is ddr3, but the 1st one has more ram even though it is only ddr2. Also, the 2nd one is an AMD II, while the 1st is an AMD 1. Which is the faster of the 2 processors as well as the faster of the 2 ram comparisons? Is there that much of a difference? The first one is cheaper, but I do need the higher specs. Is it a difference that’s really worth it, or will the first one be not that different, and still do justice?