Yes and no. Few reasons here.
Yes, because if he wants to go 16GB in the near future he can easily. He can also do what he wants with 4x8.
No because AMD lacks in memory bandwidth compared to Intel. Going to single channel (one stick) won't hamper too much performance, but it will be there. Having that much RAM isn't necessary and won't be for some times and future proofing isn't exactly an excuse either considering by the time we will utilize that much RAM his rig will be obsolete.
Also, because AMD IMCs are weak they require more volts to handle 4 sticks as opposed to only using two.
With that layed out, I'll let the two of you be the judge which route he takes. In all fairness either is fine, but as for my previously mentioned reasons going single stick isn't opportune. Try to remember, DDR3 prices are going up because DDR4 is nearing. Getting 8GB of DDR2 is super expensive (the same price for DDR3 or more) because DDR3 is here. DDR3 will do the same thing once DDR4 lands next year or 2015.