The luxe is nice, it's the pro (maybe a bit smaller) with led strips. Just look around and see what you think.
Hardware Canucks (may have spelt that wrong), linustechtips, as well as teksyndicate will likely have some decent reviews.
For 980 sli, stick with 2, until you need 3. Heck it is better to use 1 till you have to upgrade. You never need to go more than what works for you. Since you plan to have so many monitors, 2 should still be fine. Running at 4k will require 2 but work acceptable with decent fps at 3. For 1440p, 1 will work, two will work quite well.
Gigabyte Z97-sli, ud3h and ud5h will run about the same, as will the z97-a, and a few of the other asus. The only major differences to them is the bios and stock settings that come with it, but when you oc, you are usually doing it manually anyways, especially for a devil's canyon haswell cpu (tip, do it manually or you will overvolt your chip).
The z97-wifi pro from asus is equiv to the sabretooth and the maximus series, but includes wifi built in. Personally I find getting a cheap wifi card a better deal rather than pay 250. I personally use the maximus vii hero. It is a very nice looking mobo that supports 2 in sli. The soc force will give you the option to sli 4; however, it is built to the degree that it can oc with liquid nitrogen, and so on. So when I said that it is more than you need, I wasn't joking. Just keep in mind, the more in sli, the higher the likelihood that they overheat and the more you have the greater the possible requirement to put waterblocks on said gpus, which is not cheap... The gigabyte g1 is the better of the group, but will have more airflow issues when stacked with extra cards.
For everything above the medium/basic mobos, it all amounts to the physical orientation of the board, such as number of 3.0 usb ports, placement of fan headers (how many can do pwm normally, 4-pin) bios on the mobo, capacitor quality, onboard sound drivers and how the pci-e slots are shared/matched up.
The question is how far you want to go. I doubt you need 3, but I guess you would be interested in having the option. As for actual oc, you won't really need to oc a 4790k as it won't bottleneck anything for a long while, and it will take time for more games on the market to even make use of hyperthreading. It will mainly be putting the weight on gpu performance.