Nothing wrong with that combo. Only go for the skylake build if overall its cheaper, performance is equitable. The 4670k requires DDR3, the 6600k DDR4, so not knowing if you already have usable ram or not, you'll need to check prices. If the 6600k and DDR4 and motherboard is close in price, it'll be a better deal, but otherwise it's almost a moot point as far as power goes. By comparison, I have a i5-3570k and there's nothing it can't handle so far with what I've thrown at it, and see no need for upgrade presently.