I use a 40x15 wooden lath for this place. All video cards are fixed with wood screws and the HDMI port is always open for cable connection. If I'm not mistaken, then you use a 40x40 wooden beam, but it costs more.
That's my old rigs, btw! (RX 480/ R9 290,290X,295 X2)
Yep 40x40 (I think), uses what I have at the drum, except a few small parts! So basically, it almost cost me nothing if I do it myself
, but a friend of mine does it for me, all the small parts I buy plus my friend-friendly cost service, cost me around $15.
Yep, all the ports near to the handle are covered by wooden beams.
That one (ASUS RX 480) is indeed a bit troublesome, dummy output always needed to make it work on the right Hashrate.