They both run hot. The 3770k and 3570k run hot overclocked due to the IHS not being soldered directly to the cores. The 4670k and 4770k run hot overclocked because most of the VRM is on the chip. So either way, they both pretty much will net you a 4.4-4.6Ghz overclock if you have real good cooling. To be quite frank, none of the chips listed require an overclock for anything right now.
A 4770k and ASRock Extreme4 would be 478 without a combo. IMO, the Asus Z87 Pro is overpriced for what you get, plus the poop yellow is rather ugly.
If you're willing to pay the money, there is no point in spending in a dead platform. Considering, they will cost relatively the same.
Edit: Oh yea one more thing to note. Don't overspend on a motherboard, as it's rather pointless when even the basic Z boards offer the fundamental features that come with the chipset. More expensive boards give you only a few extra things. More SATA, more possible USB3, an extra PCI-E 16x slot, or even more of the latter, disregarding epeen from wasting money. For example, The Extreme4 offers not 2 but 3 full 16x PCI-E 3.0 slots, while also offering the same amount of SATA as the Asus, yet the Asus only has 2 16x 3.0 slots and is 60 bucks more. Almost any Z board will give you the same overclock unless you're going for the extreme under LN2, in which case money shouldn't be an issue anyways.
