Received new 2 budgets, which one should I choose?

Hi there!

Assuming they will get you the finished PC. Let's first start at having a look at what is common in the systems:
Intel i7-4790K CPU
Windows 8.1 64bit
DVD Optical drive (same make)
Antec TP-750C power source
Corsair graphite 230T case

Those components are the same in both builds. Non of it is rather bad, even though the CPU might be a bit overkill for gaming PC. Both companies also offered a Wireless network card, which - depending of whether you'll use it or not - is also beyond need of comparing.

Given that, let's have a look at the components that do actually differ:

RAM
Gigabyte GA-Z97X-SLI G.Skill ARES 8GB DDR3 2133Mhz [F3-2133C10D-8GAB]
versus
RAM G.Skill DIMM 8 GB DDR3-2400MHz Kit F3-2400C11D-8GXM, RipjawsX

The first set is slower, ARES is clocked at 2133MHz while Ripjaws are clocked at 2400MHz. This might be noticeable in high-demand games such as FPS, RPGS and in some non-gaming scenarios where rapid RAM operations are a must (3D modeling, CAD work). Both sets are still rather good and while I would lean towards the faster, if you don't plan to do heavy work, it might not be necessary.


Storage
Crucial MX100 2.5" SATA3 256GB SSD [CT256MX100SS]
Seagate Barracuda 7200.14 2TB SATA3 64MB [ST2000DM001]
versus
SSD Transcend TS256GSSD370 256 GB Sata 6Gbps
HDD 3.5P TOSHIBA DT01ACA200 2TB 7200RPM 64MB SATA3

Tough call here. If it were me, I'd go with the Toshiba drive because I have seen my share of malfunctioning Barracuda drives in the past, but in SSD + HDD scenario, the difference is not that critical. Regarding the Transced vs. Crucial, I'D say the MX100 gets a bit better reviews generaly, but either should be fine. To me, this is a tie, even though personally I might be a bit more inclined to buy the second set again.


GPU
MSI Nvidia GTX 970 4GB GDDR5 OC [GTX 970 4GD5 OC]
versus
ZOTAC GeForce GTX970 4GB DDR5

The first GPU has a bit more horsepower, being overclocked. However, given today's GPU performance, unless you plan to do gaming in serious conditions like 4K display, both should be fine. If you want to do some profesional 3D grpahic work, I won't hesitate to recomend the OC'd model. In my opinion, set one is better here, even if just by a notch.

I have a red flag in build one though. I have gone through the list of components, have tried putting all of them to google line by line where not sure, but I can't seem to find motherboard anywhere in the list. While the second one clearly states to be using GIGABYTE GA-Z97P-D3 mobo, the first list contains exactly zero parts that would be motherboard. Since this part can pretty much make or break the entire PC, I would be rather careful here. If you can, ask them if they included motherboard in the calculation and post their response here, because they for sure did NOT send you any in this list. While it is true that some cases come with bundled-in motherboards, this is not one of them. Not only can this difference change the price (which is alredy higher), it can actually matter a lot. As their parts are already more expensive, I'd honestly ask them and probably choose the second one, unless they send an entirely different parts to accomodate the motherboard. If it's just my oversight, pardon me there.

Cheers!