That rack has only 20" rack depth; you’ll want at least 26", preferably 28-30". In general, wall-mountable racks are for networking gear rather than servers.
StarTech 25U: https://amzn.to/2xLr7pW
L4500: [Official] Rosewill RSV-L4500 Owner's Thread
TC-RAIL-26 rails: Rack Mounting the Rosewill RSV-L4500
SM are fine, too; dive into SQ PSUs that match the PDB. 846 is expensive again now. GPUs can fit in 2U if the case is designed for it, using risers. But the L4500 is cheap and versatile.