I was looking to buy like a 5 ft rack mount but I know nothing about them. I saw antec has some cases i might buy one, like a 3 or 4U i am asuming the "U" stands for the amount it takes up vertically? no? Also what else would I need to run 3-4 headless computers over my network. I already have a rackmount ready switch, is there any brands i should look/look out for? 5ft is the max height and tell me anything else you know, thanks.