New IIfx and video card

There were very many NuBus graphics cards and most of them will work on the IIfx.

This page has many of them but not a complete list: https://www.vintageapple.org/gamba2/vid-mon-matrix.html

The card in your picture is a Macintosh Display 4•8 (630-0400), which is a good match for a 1990-era machine. It supports 1, 2, 4, and 8 bit grayscale and 2, 4, and 8 bit colormaps, which is perfect for games since some of them require 4-bit color mode (16 colors). It works perfectly with an AppleColor High Resolution RGB display (M0401), which you said you also acquired. It's even upgradable to 24-bit color by installing two VRAM SIMMs.

For photo editing (Photoshop, etc), 24 or 32 bit direct color would be desirable, and there are many expensive cards that will do that even on much larger displays. With that being said, most artists preferred to use Quadras over the IIfx. The Quadras have a faster system architecture (including enhanced NuBus speed) and are better able to handle the very large file sizes of 24-bit images. They also were heavy users of graphics accelerator boards such as SuperMac's IPA and Radius's PhotoEngine, which implemented common Photoshop filters in hardware. The PowerPC, when it was introduced, obsoleted these accelerators because it already ran filters faster than any NuBus board could.