How much VRAM do I need for hobby CAD and coding?

8GB is a reasonable starting point for those workloads. Most warnings about 8GB cards are aimed at demanding games, not ordinary coding or hobby CAD. Your code editor won't need much GPU memory if you aren't running models locally.

CAD and photo editing can use more VRAM as models, textures, images, and effects get larger. If your current projects are modest, I wouldn't pay a big premium for 16GB on capacity alone. If you expect much larger assemblies or GPU-heavy rendering, the extra room is more useful.

Check the display connections before picking a card. Two large monitors don't automatically require loads of VRAM, but the GPU still needs the right outputs and enough bandwidth for both monitors at the resolution and refresh rate you want.

Look at the monitors' input specifications too, including how you plan to use their KVM functions. That compatibility check may matter more here than choosing between 8GB and 16GB.

For the CPU, look at benchmarks for the specific CAD and development tasks you care about rather than assuming more cores will always feel faster. Responsive single-core performance is useful for interactive work, while builds and other parallel tasks can benefit from more cores.

Since system RAM has already been a constraint, I'd put some budget there too. It's separate from dedicated GPU memory, and a bigger graphics card won't fix a shortage of system RAM.

A desktop Mac is another small-form-factor option if you're happy staying with macOS. Check its support for both monitors and choose the memory configuration carefully. Apple silicon uses unified memory rather than a separate pool of dedicated VRAM.

That said, a PC may be the better fit if matching the work machine's operating system and keyboard layout is a priority.