OPNSense images... IMG files?

[tbird635]

I am trying to figure out what I am doing wrong. I downloaded and tried all the images and they appear to be disk images like PFSense, and not actual installers. I'm using rufus to write it. It's going on a Lanner Electronics FW-7551B-NG1 (like the Netgate 7551)
 

dvd: ISO installer image with live system capabilities running in VGA mode. On amd64, UEFI boot is supported as well.
vga: USB installer image with live system capabilities running in VGA mode as GPT boot. On amd64, UEFI boot is supported as well.
serial: USB installer image with live system capabilities running in serial console (115200) mode as MBR boot.
nano: a preinstalled serial image for USB sticks, SD or CF cards as MBR boot. These images are 3G in size and automatically adapt to the installed media size after first boot.

Are these similar to PFSense in that you get a menu to install at the start of the boot and I'm missing that somewhere? ( I installed pFSense no issues  pfSense-CE-memstick-serial-2.5.1-RELEASE-amd64.img)

I need a serial image, no VGA on this box, preferably cf card, but I can go SATA (non efi). If I'm missing it, is it because of my older system's inability to UEFI boot ? If so, can I disable it? Is the serial console enabled on anything but the serial and nano image?

Thanks for any help. I know I'm missing something obvious somewhere.

[Patrick M. Hausen]

Write the serial image to a USB drive using dd or any other imaging tool. Boot, install.

If you can get it to boot you will be greeted with a login prompt at the console. You can then use it as a "live system" logging in as "root", connecting via browser to the Ui etc. Or you can login as user "installer" and get the regular old fashioned console based installer.

What about this in the documentation is unclear, if I may ask?