Question shows poor research so not +1ing it, but it's innocent enough so not -1ing either...
First part: You need to use GPT and UEFI together. EFI System Partition is only supported on GPT disk. You can also just format your disk as GPT (this is supported even for extremely old hardware) and not use UEFI; the PC BIOS should be able to boot from a GPT disk. I was doing this way back in the "Core 2 Duo" days.
Windows 8 will install on a MBR / PC BIOS system. See Will my computer be able to run Windows 8 without UEFI?
Second part: The earliest Intel CPUs (more accurately, motherboards) supporting UEFI were the Sandy Bridge as you said. So the Sandy Bridge and Ivy Bridge CPUs are the current production CPU generations supporting UEFI.