the 3700+ is almost as fast as the 939 4000+.. so dont be sad about this fact. You'll likely upgrade all your setup with new thing when the 3700+ will be outdated.
There wont be any single core CPU for 939 according to AMD. The X2 are good, but the newer one, for socket M2 will support up to date component and likely to be faster.
So, get either the 3400+ or the 3700+(both 2.4 GHz, but one with 512k cache and the other, 1 meg) and make your current setup last until socket M2, DDR2, and all the best that are to come.
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