Please Assist in Choosing a new High-End i7 + Mobo Combo

[invizo]

Hello,
Before I go into what I am looking for:
I am trying to fix a problem that has plagued nearly all of my newer games. I get the most ridiculous stutters while my CPU and GPU usage sits at 60% or lower. My rig may already seem high-end but I believe the motherboard is the culprit; this problem became worse when I upgraded to 1440p.

Windows 8.1
Multiple Corsair SSDs
Intel i7 3770K ~ 4.4GHz stable overclock
Asus P8P67 Pro Motherboard (purchased years ago for ~$140 with an older i5 2500K CPU)
16GB DDR2 Corsair 2100+MHz (details escape me)
nVidia 780GTX 3GB Factory OC
Corsair 750Watt PSU
NZXT Closed Loop CPU Water Cooler ~ Stable 42C liquid temperature, max of 50C
Asus 27" 2560x1440p Monitor


As you can see, I upgraded an older 2500K i5 CPU to an i7 that shared the same socket type, which I think shot me in the foot as far as CPU throughput or something. Borderlands 2 on ultra settings right now gives me 35-45FPS in heavy action scenes with low CPU & GPU usage (yes the gpu is doing the physx).

Rather than spend $200 or so to fix the legacy motherboard, please recommend a Motherboard + CPU i7 Combo in the ballpark of $600. I don't mind spending more or less than this amount, but only if the $/performance is worth it. I have already accounted for the DDR3 upgrade price separately.

I had my eye on the newer i7s that were supposed to come out this last summer with the newest mobo chipsets from Asus.

 

[Darkbreeze]

Not sure what's holding you back but that card should be capable of averaging 58-62 fps with a single card. I think there must be something in a setting somewhere. If you have the chance run GPU-Z like I said and post a screenshot.