this guy came to me one day and asked for a solid, clean build that he will use for a long time. He's a heavy gamer, plays most of the mayor titles, and does some light audio production. i went and serup a parts list for him
It's a hard one thing judge but in my opinion it seems quite expensive, in the sense that the price to performance isn't quite there. To answer your question directly, is it a good build? Of course it is, its $2500, and if your friend is fine paying that much, then sure. But there's definitely work that could be done to squeeze more performance out of that amount of money.
Firstly, haswell is nice and new, but its all just so damn expensive right now, especially stuff like the sabertooth series mobos. You could get a slightly cheaper ivy bridge motherboard with an i7-3770k, over clock it to its popular 4.6GHz, and will perform as well as a stock 4770k.
Next, as the H440 has the room, I'd shoot for a 240mm top mounted cooler.
In my personal opinion, even 1 TB of ssds, which I hope you'd put in raid 0, is also much more expensive than what its worth as ssd tech is changing so quickly. At that price point you might as well go for a much smaller but faster msata drive over the PCI bus.
So to start the 4670k isn't from haswell refresh which means it had really crappy thermal paste and caused increased temps. I upped it to a 4690k as the problem is fixed with this CPU and it's cheaper. The 4690k also supports dual channel memory so I change the ram kit to something that will be much faster.Last but not least the 970 currently has a problem with it's vram due to Nvidia lying to the consumer, so I upped it to a 980. Oh I almost forgot I changed the cooler to a Phanteks which will provide a cooler and quieter user experience.
As far as keyboard and mouse goes let the guy choose those to his own liking. If he doesn't have much experience with mechanical keyboards picking up a key tester from wasd keyboards wouldn't hurt. Anyways the links to the tester and build are posted below.