Use a dedicated switcher like the ATEM Television Studio HD.
https://www.blackmagicdesign.com/products/atemtelevisionstudio/techspecs/W-APS-08Use a BMD HyperDeck Studio Mini to record. A Teradek VidiU Pro to stream/record.
Use your computer to control the switcher and build graphics. Even use PowerPoint as an input for graphics, video playback, live titles and lower thirds with the SimpleSupers.com app.
You will have a lot of flexibility to add cameras in the future, or other inputs if needed. The hardware does the work and frees your computer up for other tasks.
kc