Yes, with gtx 980ti which Is too powerful for this system, i just got a good deal for it.
I generally dont recommend buying used GPU:s since there is ALWAYS some problem with them.
I would say GTX 1060 is sweet spot if you have oc:d cpu around 4ghz with ram running 2133mhz, if not then settle for 1050ti or 970 with stock i7. From older gpu:s i would say 780ti is a good choice, but 10 and 9 series has better optimatizaion you can lose some performance with 700 and even 900 series.
Actually Asus P7P55D is my main choice when overclocking lynnfield.
Your motherboard is same series but its slightly smaller form factor with same chipset and quality components.
P7p55d has 12+2 power phases and your model has 8+2 which is not bad at all, i never had your motherboard but seeing it has same chipset im sure you can hit decent overclock with it (if your into it)
I didnt take into consideration about you running the cpu on stock speeds, for example x3440 xeon runs all cores at 2.5ghz, i would never recommend it unless you try to get it running atleast 3.6-3.8ghz. Which surely is possible with that motherboard, i would say even 4ghz is average overclock with that.
Most important thing is quality power supply i have used Evga supernova G2 650w model, its slightly better than newer G3 but that is good unit too, someone else with more knowledge on power supplies can give you better options since i only used EVGA mainly there might be cheaper and better options.
For cpu and ram recommendation cant really suggest much before we know, are you about to overclock it? Are you getting quality power supply? Around 30$ for new cpu cooler is needed too if you overclock it.