Okay, first rule is, put the slow (30 minute) drives into the first room, fast drives go in the second room.
Are you downloading the file simultaneously to each machine from a single source? Will you source actually do five minutes, or will it bog down under 30x load.
You'll take a huge time penalty on yourself, moving from machine to machine.
Plug in the USB, direct download to USB, so you touch each machine once. 35 minutes. Figure 90 seconds to set up each machine, times 30, that's 1.5 x 30 is 45 minutes just for setup. Add 35 to that once, and you get 80 minutes.