A choice between 1070 GPUs

Hi!

I'm making 4 minings farms with 4x GPUs on each of it.

Im having a dillema what to choose to not get broken GPU after a couple of months.

Here is what i chose to buy:

1. GIGABYTE GeForce GTX 1070 1582Mhz PCI-E 3.0 8192Mb (GV-N1070WF2OC-8GD) 442$

2. Palit DUAL GeForce GTX 1070 1506Mhz PCI-E 3.0 8192Mb (NE51070015P2-1043D) 442$

3. Inno3D GeForce GTX 1070 1506Mhz PCI-E 3.0 8192Mb 8000Mhz (N1070-1SDN-P5DN) 442$

and i little bit more expensive choice

4. Palit JetStream GeForce GTX 1070 1506Mhz PCI-E 3.0 8192Mb 8000Mhz (NE51070015P2-1041J) 482$

5. GIGABYTE GeForce GTX 1070 1607Mhz PCI-E 3.0 8192Mb 8008Mhz (GV-N1070G1_ROCK-8GD) 477$

6. Palit Gamerock GeForce GTX 1070 1556Mhz PCI-E 3.0 8192Mb 8000Mhz (NE51070T15P2-1041G) 491$

Also I have this interesting option to buy

7. PALIT GeForce GTX 1070, PA-GTX1070 SUPER JETSTREAM 8G, 8Гб, GDDR5, Ret [ne51070s15p2-1041j] - cost 500$ and have as much clock speed as 1080 with 6 pins and 150 TPD

What could be the best choice here?

I already have 2x NE51070015P2-1043D bought them a couple of days ago. They are mining fine but what scares me is quality of this GPUs. I read that the cheapest versions have some issues compared to a ittle bit more expensive ones.

By the way here is what i get on this GPU:

80 downvolt, 250 core, 600 clock giving 435 sol with 60 degree in warm room against 477 sols on 112 undervolt, 250 core, 600 clock.

435 sol : 91.1% (477 sol) : 8.9% sols lower
80% downvolt : 71.4% (112% voltage) : 40.6% economy

What can you suggest on GPU choosin thought?

Thanks!