CPU: Intel Core i5-7600 3.5GHz Quad-Core Processor ($209.99 @ SuperBiiz)
Motherboard: ASRock B250M Pro4 Micro ATX LGA1151 Motherboard ($77.98 @ Newegg)
Memory: G.Skill NT Series 8GB (2 x 4GB) DDR4-2400 Memory ($57.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($46.88 @ OutletPC)
Video Card: MSI Radeon RX 480 8GB ARMOR 8G OC Video Card ($214.98 @ Newegg)
Case: Fractal Design Core 1000 USB 3.0 MicroATX Mid Tower Case ($38.99 @ SuperBiiz)
Power Supply: Corsair CXM 550W 80+ Bronze Certified Semi-Modular ATX Power Supply ($43.98 @ Newegg)
Monitor: AOC G2460PF 24.0" 1920x1080 144Hz Monitor ($219.97 @ Amazon)
Keyboard: Corsair Vengeance K65 Compact Mechanical Gaming Keyboard Wired Gaming Keyboard ($69.99 @ Newegg)
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-03-22 14:16 EDT-0400
7600 is the 6600's successor. Slightly faster, same price.
Don't buy ITX mobos unless you are actually going for an ITX build. At that point you pay for them being smaller and having less features.
With micro ATX you can get 4 RAM slots (and you should) so you can get 2x4GB, use dual channel and still be able to upgrade.
Faster and cheaper HDD.
That PSU is currently on sale and much better. Deals will change though.
Don't buy the VG248QE. Also this monitor got FreeSync, which is nice.
Not a fan of Corsair keyboards, but let's not go down that rabit hole yet.
I'd stretch the budget a bit to include and SSD.
Also keep in mind that an i5 is usally not enough for streaming, unless you're willing to sacrifice a lot of fps and quality.
If you can wait until April get an AMD Ryzen 5 1600 (219$ afaik). 6 cores / 12 threads are much better for streaming than 4 cores / 4 threads. You can also oc it and get it to about the same speed as the i5-7600 so there's not many reasons to not get it instead of the i5.