you should say your budget…
Cheaper version:
i7 3770k (almost 8 in cinebench and 10 with OC) + 16/32gb ram + SSD
The expensive one
I7 3930X (10 in cinebench and 13 with OC) + 16/32gb ram + SSD
About videocard, you don`t need an expensive one. C4d is using the CPU for rendering, not the gpu… If you really want one you could try the nvidia 640 or above.
Florin