|"I can't find much for AM3 processor online anymore"|
Newegg has a ton of them, but they're listed as HP CPUs, not AMD.
Looking at your specs, the CPU is the least of your problems. You could use more RAM, you have an old Radeon HD 4000 series video card, & you already know the limitations of your HDDs.
The black edition X6 might be easier to overclock, but it's default clock speed is just 100MHz higher than your X2. It's also rated at 125W vs 80W for the X2. How many programs will actually take full advantage of 6 cores? I suggest you go for an X4 instead. If you're running Win7 64-bit, put the savings toward more RAM.