I seriously cannot wait for the Volta GPU's to arrive. Man this Titan V is fast compared to Titan Xp and 1080Ti. I am for sure upgrading my GTX 1070 to a Volta around 600-700 bucks ball park next year.
Yes Bose are too much $$ but the sounds are outstanding...
As for the new Logitech surround sound...well the two on my counter space lack something...but overall they are well worth the money...I think I am going to keep them !
That motherboard is pretty sweet, it has a built-in water cooling setup, so you just buy the watercooler and can easily hook it up. That video card should last him a year with ULTRA settings games. Most of these dev's use previous game engines and hardly modify anything. Like the Call of duty series. That processor isn't bad but i'd get the i7 7700K, some games do use more cores, not sure which games he plays. I would get him a M.2 hard drive instead of SATA, if your motherboard supports it then get it, it's really fast compared to SATA hard drives. I left you a pic below regarding the hard drive.