I may be wrong but I think once you go for the 16GB and 512 SSD, the config also becomes 8 cores.
It's all good. I ended up with the 7C 8GR + 1TB HD because the wife can't get the size of her photos library small enough not to concern me about her using all or most of the internal storage on a 512HD. And I'd rather not have her faff about with an external. Things you do for love...