Sorry it's taken me so long to respond, I've had a lot of school work recently.
I would recommend to your customer the following:
-i5 4690K.
-Any Z97 motherboard from ASUS, MSI, ASRock, or Gigabyte.
-R9 290 or R9 290X from XFX, ASUS, Gigabyte, MSI, PowerColor, or Sapphire.
-8GB or CL-9 or below, 1600+ MHz RAM, 2 sticks of 4GB.
-Cooler Master Hyper 212 EVO cooler.
-27", 1440p IPS display if possible. If not go for 1080p. Less than 5ms response time.
-Any case from Corsair, Cooler Master, NZXT, or really any case that has multiple fan mounts, good cable management, and that the customer likes. A good middle of the road case is the NZXT H440 or the Corsair 450D.
-Any XFX or SeaSonic powersupply, at least 550 watts.