My current system (R9 290x, i5 2500k, Crucial M4 60GB SSD, WD CB 500GB HDD,, 2x4GB DDR3, Gigabyte p67x-UD3-B3 mobo, Corsair TX 750v2 psu, Cooler Master 932 HAF Advance case) is getting up there in years and the performance I'm getting in newer titles isn't quite what I'm looking for. So I'm looking to build a new one (sometime this upcoming week). I already have mouse, keyboard, a monitor (though I'd love to get myself an ultrawide) and speakers. At this point I'm struggling to pull a stable 60FPS at 1080p with medium-high settings in most of the titles I play. Ideally I'd like to move up to an ultrawide resolution or perhaps 4k if it's doable, and still play at 60FPS (would also like 120-144 if it's doable). My budget is around $1200, but I'd be willing to go up to $1400 max if a little extra cab go a long way in terms of CPU/GPU performance.
TLDR: Need a new system in the range of $1200-$1400. Have most peripherals.