I'm building a cryptocurrency GPU mining rig inside a 4U Rosewill server case/chassis. I'm doing this because the typical open-air frame setup is not ideal for where my rig will be located. I know that some people have built rigs like this before by removing drive bays and other non-essential removables from the inside of a server chassis to make room, and then mounting the GPUs on some type of DIY rail or frame that they either made, modified or bought and then rigged to the inside of the chassis. Does anyone know where I can find this type of rail or part? Other suggestions on how to mount multiple GPUs inside a server chassis are welcome. Thanks