The chip is easy - i5-4690K. It's stock clock is 100MHz higher, which isn't a big deal, but it has better thermal properties (improved TIM) so at clocks below 4.4GHz it'll run much cooler (@10C). You'll still want to get a good cooler, either way.
If you go with the 4690K, you might as well get a Z97 board to match although it will run on a Z87 with a BIOS update. You really ought to take a look at the Hero VII - same performance but cheaper if you don't need the Sabertooth bells and whistles. Do a side-by-side comparison at the Asus website.
If you're not already using it, pcpartpicker is a great site for putting together a build, checking compatibility, and tracking prices. If you register there (it's free), you can open the link below and save it under your own profile, then swap components in and out until you've got a perfect mix.
PCPartPicker part list:
http://pcpartpicker.com/p/DxYXYJ
Price breakdown by merchant: http://pcpartpicker.com/p/DxYXYJ/by_merchant/
CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor ($199.99 @ Micro Center)
Motherboard: Asus MAXIMUS VII HERO ATX LGA1150 Motherboard ($199.99 @ NCIX US)
Total: $399.98
Prices include shipping, taxes, and discounts when available