For 3U/4U I like iStarUSA cases. I went for 4U for the quieter 120mm fans and so it can fit half-hight bays sideways on the front panel. Here's my video encoding workstation in an iStarUSA D-400L-7SE: https://imgur.com/a/YLjDX0e
You can also spring for their matching drive bays http://www.istarusa.com/en/istarusa/product_speclist.php?ser...