CPU: You will want to go with the best CPU you can. Due to how streaming works, the CPU is the most important part. To get the best quality stream, you will want to use the X264 encoder(Both in OBS and Xsplit).
General recommendations for CPU’s:

• Any of the following or newer Intel Core i7 CPU’s, with better ones in descending order.
• Core i7 2600k
• Core i7 3770k
• Core i7 4770k
• Core i7 4790k
• Core i7 6700k
• Core i7 5820k
• Core i7 5930k
• Core i7 5960x

AMD CPU’s are not recommended for streaming as they have very low IPC(Instructions-per-clock) performance. A top-of-the-line AMD 8350 CPU will perform as well or maybe worse as a i7 2600k, a 4 year old Intel CPU.

Ram: Ram is not very important when streaming. Typically, when using a program like OBS, no more than 500MB will be used. Of course, this may very depending on the amount of source, plugins etc.
General recommendation for ram:

• 8GB DDR3 or higher

GPU: The GPU is the next most essential part of streaming. Popular programs like OBS, Xsplit and others perform actions on the GPU, like compositing, which is when the game video, webcam video, overlays, etc are all mixed into one picture, and scaling, which when your stream is converted from 1080p to 720p. Other actions include anti-alising(Experimental in Xsplit), which can be applied after scaling to increase the quality, and other effects.

General recommendation for GPU:

• Nvidia – Any GTX 650 series or higher (700, 900)
• AMD – Any Radeon 6850 series or higher (7000, R7, R9)

CPU:

Ram:

4GB DDR3 or higher

Internet Speed (Wired or Wireless)