Burnout

So recently I built my first computer and am having trouble deciding what resolution to go with to do my gpu justice i'm currently running a EVGA 1070 FTW but I would like to eventually run a pair in SLI given that eventually i will be adding another gpu what would be the better choice for some competitive gaming though the majority of it is casual 1440p @ 144hz or 4k @ 60hz and for either resolution what monitor would you suggest?

Thanks, and I know the PSU is overkill for now I was just giving myself room to work with right now since I wasn't entirely sure how much power the 1070s would require

Yea for the most part though I want to put a good amount into the pc so it'll last me a while and I have the option to upgrade in the future. And thanks for the suggestion!

Hey all I'd like some help determining whether or not the parts I've chosen are compatible for my first PC.I know PcPartPicker can very helpful though its not entirely reliable my issue though is I'm not sure what I should be double checking for compatibility. Hopefully you can help me out. Any and all help would be greatly appreciated. Thanks in advance! http://pcpartpicker.com/p/X6wwt6 CPU: Intel Core i7-6700K 4.0GHz Quad-Core Processor CPU Cooler: Corsair H100i 77.0 CFM Liquid CPU Cooler Motherboard: MSI Z170A KRAIT GAMING 3X ATX LGA1151 Motherboard RAM: Corsair Dominator Platinum 16GB (2 x 8GB) DDR4-3000 Memory Storage Device: Samsung 850 EVO-Series 1TB 2.5" Solid State Drive GPU: Nvidia GTX 1070 when it comes out Case: NZXT H440 (White/Black) ATX Mid Tower Case PSU: Corsair RMx 750W 80+ Gold Certified Fully-Modular ATX Power Supply Optical Drive: External LG optical drive as the case doesn't have one OS: Microsoft Windows 8.1 OEM (64-bit)