The Wirecast studio utilises Thunderbolt 2 based computer hardware, and HDMI and high quality USB based cameras.
495 Thunderbolt Hub UltraStudio Express 150 HDMI Camera 160 2x USB Cameras 400 Wirecast Software 60 USB cables 40 HDMI cables 400 Projector SUM
This is a bit old - but still good from Marc Bretzfelder - Streaming Media Producer at the Smithsonian Institution - Bretzfelderm@si.edu - slideshare.net 
HDMI Converter
A converter is required in order to convert HDMI signals from a camera into something that the computer understands.
The UltraStudio Mini Recorder is an ultra small pocket sized Thunderbolt powered recording from SDI and HDMI - blackmagicdesign.com
If you only have one HDMI camera and you want to se it for streaming or high quality recording direct to disk - this device looks perfect. I'll check it out with the guys in the shop before confirming but the UltraStudio Mini Recorder is what I am recommending.
The UltraStudio Express is a Thunderbolt 2 powered capture and playback with SDI, HDMI, analog, with pro and consumer cables.