If you're willing to go 12% over budget, the following is a true "professional" workstation class computer.
CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($247.94 @ SuperBiiz)
Best value workstation CPU available right now. Same performance as more expensive i7 but with ECC memory support.
CPU Cooler: Arctic Cooling Freezer i11 74.0 CFM CPU Cooler ($22.99 @ Amazon)
These are great quality, easy to install CPU coolers that will run very quietly on a <100W CPU.
Motherboard: ASRock Rack C226 WS+ ($238.99 @ Superbiiz)
C226 chipset for ECC memory support and better IO performance for workstation use. 10X SATA ports for future storage expansion.
Memory: Samsung DDR3-1600 8GB/1Gx72 ECC CL11 Server Memory ($91.99 @ Superbiiz)
ECC memory, add more later as needed, (make sure to buy the same model of DIMM when adding more).
Storage: Intel 520 Series Cherryville 120GB 2.5" Solid State Drive ($64.99 @ Amazon)
OS/Application drive. Fast boot/launch.
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($82.99 @ NCIX US)
Project/media storage. These are good for video editing as they can sustain nearly 200MB/s, far more than most amateur footage, which comes in handy for sequences with many layers (video collage?).
Video Card: EVGA GeForce GTX 750 Ti 2GB Superclocked Video Card ($139.99 @ Amazon)
Maxwell architecture offers superb GPGPU performance at a very low power dissipation level.
Case: Fractal Design Define R4 w/Window (Black Pearl) ATX Mid Tower Case ($79.99 @ Newegg)
8X 3.5" drive bays, 2x 5.25" bays. Great air-flow and cable management, professional appearance, room to grow.
Power Supply: SeaSonic S12G 650W 80+ Gold Certified ATX Power Supply ($96.50 @ Newegg)
The system as configured above would run fine on a 200W PSU, so this is vastly overkill in terms of wattage. I have selected this because it is one of the few <$100 PSUs that has 10 SATA ports and 4X 6-pin PCIE connections. (upgrade path to something like dual GTX970/980 or similar if you wanted to leverage GPGPU accelerated encoding and color correction in the future, and of course, plenty of connections for more hard drives).
Optical Drive: Pioneer BDR-209DBK Blu-Ray/DVD/CD Writer ($54.99 @ Amazon)
Blue ray burner.
Total: ~$1120 shipped