Will you be storing files on it (video, music) or streaming from another source? Add a HDD to this if you need space.
PCPartPicker part list:
http://ca.pcpartpicker.com/p/Pr26pg
Price breakdown by merchant: http://ca.pcpartpicker.com/p/Pr26pg/by_merchant/
CPU: Intel Pentium G3240 3.1GHz Dual-Core Processor ($60.05 @ DirectCanada)
Motherboard: MSI H97M-G43 Micro ATX LGA1150 Motherboard ($90.40 @ DirectCanada)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($84.79 @ DirectCanada)
Storage: A-Data Premier Pro SP600 128GB 2.5" Solid State Drive ($59.99 @ NCIX)
Case: Silverstone ML03B HTPC Case ($58.01 @ DirectCanada)
Power Supply: Antec High Current Gamer 400W 80+ Bronze Certified Semi-Modular ATX Power Supply ($44.99 @ Memory Express)
Total: $398.23
Prices include shipping, taxes, and discounts when available