Addressing the initial comparison between the two boards graphics support: none of that means anything once you plug in a GPU, so those differences are moot.
You won't be able to tell between PCIe and PCIe 2.0 for things like WiFi and USB add-on cards. Since it's a not a server, you won't be able to use more than one Ethernet port--and you're using WiFi anyway, so the difference doesn't matter.
You aren't using enough SATA ports to justify getting the Deluxe, and since you're not building an NAS, I doubt you'd need more than 16TB of data (four 4TB drives on the SATA 3Gb/s ports). You haven't mentioned a need for eSATA, and USB3.0 is as fast or faster anyway while being more common.
I doubt you'll have 4 peripherals that need USB3.0. USB2.0 is more than enough for things like mice and keyboards. WiFi and Bluetooth together are worth AT MOST $40. You don't need over 8 power phases since I doubt you're planning on sending hundreds of watts through the motherboard looking for a 6GHz overclock using liquid nitrogen.
The sound quality is the one thing I'd admit to being better on the Deluxe. Then again, you can get a Creative X-Fi Titanium for roughly $100 which will absolutely destroy the Deluxe's sound ability (and unless you're doing surround sound gaming or studio recordings, you won't notice any difference between the Deluxe and the LK to begin with).
I'm not saying spending extra money is always a bad idea, but you could at least put it into peripherals that matter (144Hz monitor or 1600p monitor, a better liquid cooling loop, a better case, and so on).