Hi! Just looking for a part list here - I'm more used to building high-end gaming builds, but my father asked for a speedy productivity PC capable of running 3-4 monitors with no problems. I have no other requirements besides a durable mini-itx build, and I already have a spare (somewhat used) i7 - 4790k that I would love to use. I have no hard capped budget, but especially since I already have a CPU, sub $600 would be appreciated. (Given it's for work, a rather inconspicuous case would be nice too.) Thank you!