Go for a i2500k if gaming is your thing. The Hyper Threading feature present in the i2600k doesn't do much for games. If you're planning to do a lot of video and 3D work then a i2600k is a better choice over the i2500k.
You don't need 16GB of RAM for gaming either. 4 is good, 8 is more than enough, 16 is just overkill. You won't be using all the RAM for gaming. If you're doing other things besides gaming, then 16GB will be a good fit.
Why not a 80 Plus Gold PSU? Corsair has some of the best ones out there. I'm using one and it is ridiculously silent and efficient. That's gonna save you a lot of $$ in the future. $$ you can use for future upgrades.
The case is another very important feature of a first build. The case has to be future ready and it needs to have a lot of good airflow to keep your components cool. Corsair and Cooler Master make some of the best cases out there. I have a Corsair 500R. It's a pretty awesome case with tons of cable management capabilities. There's also tons of room for fan expansion and water cooling if you plan to go for those. If you're running a SLI configuration, having the space for it in your case is not good enough. You need good airflow to keep your GPU's cool since GPU's in a SLI/Crossfire configuration run hotter than in single GPU config. The 400R from Corsair will be something that will go very well with the rest of the configuration.
The CPU cooler is great. Be careful, though, I've heard that those fins can cut you very easily if you're not careful.
I have a Maximus IV Gene-Z so I have to ask. Will you be using the Intel Smart Response Technology? Or will you be using your SSD as a boot drive?
Good luck and have fun. I just put together my first build not too long ago so I know how you feel. I did a lot of research on the matter. I'm no expert, but I hope my tips were helpful.