if you don't want to overclock, then an AMD Black Edition is a waste of money. A "non-Black" Phemon should be significantly cheaper andd not much slower.
Intel's Core2duo is being phased out - I am not sure if you plan upgrading in future.
As for the i3/i5: the i5 can "overclock" itself on demand, I forgot the marketing expression for that feature. Please be aware that some features of intel CPUs are only available if these are combined with certain motherboard chipsets. This is not a technical, but a marketing decision.
In my opinion, the performance differences between the AMD and the i5 is not very high, so you want to look for the price/performance balance. You need to take into account CPU and motherboard. Also take into account the features and interfaces your new system "must have". For example, Intel has ditched the PATA interface, and they are now starting to get rid of the PCI slots. Motherboard manufacturers need then to solder 3rd party interface chips onto the boards which makes the stuff more expensive and adds additional compatibility problem sources. Oh, Intel based motherboards are not yet Sata-6GB ready. Unlike the new AMD chipsets.