**BEST CLUSTER RACK?*\*

Looking to build a few Pi's to run a few FLUX nodes from. What is the best cluster rack that can support at least four Pi 4s? GeekPI has a few, such as this one and this one for almost twice as much. Are they any good, especially for cooling? I can't even tell if there's room to connect an SSD to each, whether SATA 2.5 or M.2's.Thanks!