Base your build around the LGA 1151 standard and the new Skylake CPU's. There's no strong reason why you shouldn't go up to Skylake, unless a $40 change in price means that much to you, in which case you can modify your purchase since you're already spending around $1850.
Change the Hard Drive; you shouldn't be using a 5400rpm HDD in a desktop computer. Those are for laptops. You should honestly do a SSD + HDD setup, or pure SSD if you're spending this much money.
Are you an audiophile? If not, then save your money and skip the sound card. A sound card is a want, not a need, for most people.
I'm guessing the desktop will be reliant on a wifi connection to access the Internet?
I'm imagining you're planning to play PC games on this computer. If so, pick a better keyboard and mouse. What's interesting is you got a stain/spill resistant keyboard that's $10 via NCIXUS, but anywhere else it's like $40 (guessing the other retailers don't sell or have access to it anymore). Either way, it's silent keyboard (makes less sound when typing) and has surface to resist spills. For gaming, there's no real reason why you should use this. There's a lot of available keyboards to choose. As for the mouse, well, you got a mouse wheel, and 3 total buttons (left/right/wheel). My deathadder has 5; left, right, wheel, thumb1, thumb2. May not mean a lot to some, but it does make a difference to me.