Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.
i thought amd as said the phenom B3's is the last for AM2+?Well...
You have two choices that seem sensible to me.
1. Buy 5000+ Black Edition and overclock it to 6400+ levels and beyond if you can. It will get you approximately the performance of the top of the line AMD dual core.
2. Buy one of the new B3 Phenoms and try to overclock it (the easiest one to overclock is the high end 9850 but i am clueless with amd overclocking as i got into overclocking when i bought my current quad.
Pesonally i would buy the 5000+ Black edition. AMD's refresh of Phenom, codename Shangai, is supposed to be out relatively soon. I think its going to be 45nm and should prove to be a better clocker than the current crop. As the socket will stay the same AM2+ i think this is better as most games dont use the Quads that much anyway.
Do let us know of what you will do and the performance increases you get/overclocking results. I love hearing AMD overclocking stories as they seem to be harder to pull compared with the intel set ups and require more skill as well.