This is my recommended system for live streaming with a multi-camera system. (*click image to see it full size. Numbers on diagram correspond to equipment list below.)
C – Multi-Camera System
1. Computer: HP Elite Desk i7 Processor, 16GB RAM.
2. Video Interface: AJA U-tap SDI
3. HDMI Camera: Canon R800($200) | Canon G40($1,000)
4. HDMI-mini to HDMI cable
5. HDMI-to-SDI Converter: Blackmagic Microconverter
6. SDI Cables (Choose your lengths)
7. Video Switcher: Blackmagic Designs TVS HD
8. SDI Camera: Canon XF205 ($3,000)
9. Multiview Monitor: Samsung LED 32″
10. Tripod: Good ($250) | Better ($550) (not pictured in diagram)