If the G7 series servers have a motherboard that supports the ES1000 chipset, it should be possible to use it. It's just a matter of finding the right motherboard. Intel has the ES1000 chipset available for Motherboards, and it's just a matter of finding a motherboard that has the correct chipset to boot into Windows Server 2012.
The only way I have been able to configure resolutions for the onboard video cards are by using the free ATI video drivers. I should be able to use them for Windows Server 2012 as well. This is why I have tested the drivers on Windows Server 2012.
All of the HP G7 series servers appear to be the same model. This is the HP G7-45G7H-UN8. This is a 6U server with four hard drives and two SSD drives. I have tried all four of the SSD drives, and two of the hard drives. I have also tried all 8 of the onboard video cards. I have managed to find drivers for the onboard video cards for all of my servers, but only the 1G43 driver is for use with Windows Server 2012, and only runs on 2008 & 2008 R2. The other cards I have can be found on the ATI site. I have also been able to use the onboard video cards for booting into both Safe Mode and Single User Mode, but the resolutions are very limited.
As for my video card, I will be purchasing the NVIDIA Quadro K620. It supports the versions of Windows Server 2012 that I have tested it on, and its able to make use of the 4 additional onboard video cards. I have also been able to make use of all of my available onboard video cards as well. If I had the hardware to support NVIDIA's latest drivers, I would be using their latest NVIDIA drivers. 827ec27edc