The Netgate ADI image only supports a serial installation from memstick and does not come with VGA option. The amd64 architecture (which works even on Intel 64-bit CPUs) can address more memory and may have other performance advantages, but requires a compatible CPU.
If you have a 64-bit capable CPU, use the amd64 version.
You can determine the files needed for your install by reading the rest of this page for guidance.
