PC Upgrade - Which to choose?

[Powerbolt]

So I'm planning on doing an upgrade sometime in the near future, and I haven't a specific upgrade set in stone yet as to which one to settle on. As of late, I had a single SATA port go out on my MSI mother board. Not too worried about it as I have 5 more, 2 of which aren't even being used. Here are the few upgrade options I've been thinking about, and current specs.

System Specs:
CPU : Intel Core i7 4770K @ 4.2GHz
Motherboard : MSI Z87-G45 Gaming (Supports 2x SLI)
Memory : Corsair Vengeance Pro 8GB x 2 @ 2400MHz
GPU : EVGA GeForce GTX 780 w/ACX
PSU : ThermalTake 750W SmartSeries
Monitor : BenQ 24" LED RL2450HT 1080P

Upgrade #1.) Swap out motherboards for an ASUS Maximus VI Extreme, or some such equivalent. Preferably one that is able to support 3-4x SLI. Also a better quality PSU to better supply the system (800W or better).

Upgrade #2.) Remove my dedicated Physx card (not even worth keeping in as it is.), and fit in a second GTX 780 of the same model in SLI. I'm thinking two 780s would utterly destroy a single 1080p monitor, and that they would be better suited for a dual monitor, or single 1440P setup.

Upgrade #3.) Trade out the 1080p monitor for a nice 24-27" 1440p monitor.

Upgrade #4.) Get a second BenQ 24" monitor and setup dual monitors.

I'm open to other suggestions. I'm just speculating on what would be a viable replacement for the weakest links in my current setup.

 

[LavyDunois]

Upgrade #1.) That MSI mobo is fine. 3/4 way SLI are from what i've read horribly supported software side. You would also need a huge case/psu.

Upgrade #2.) Even 1 Gtx780 is overkill. No need for a 2nd unless you are going to run 8 monitors @ 1080p or something unnecesary like that.

Upgrade #3.) This Gpu was partially build for that resolution and probably on 2/3 monitors.

Upgrade #4.) This might be the best one. I am running 2 monitors @ 1080p on my asus gtx780 directcu ii oc and i love it.