[question] worthwhile GPU that fits in a 3U chassis?

I built a system around a 3U chassis, then tried to stuff a GPU in the box and couldn’t close the lid. I got a 4U chassis and rebuilt the system, but I still have the 3U and I’m thinking about filling it back out so I have a failover for Proxmox. Is there a GPU I should consider or just stick with the integrated graphics?...