Live event with 4 HD Cameras

Hello!
Somebody can help me with workflow of Live event, that will broadcasting into the internet?

1st I need to choose 4 HD cameras and the way of capture them into PC, i'm looking on DeckLink quad, or there is another way?

2nd I need some video software mixer, i'm looking on xsplit, but there can't say to me, how it works with deckling.

Thank you.

Decklink cards are great, just remember these are HD/SD inputs, you need camera's with these connections, especially if you want to work with 4 of them. You do need some switching software. Take a look at VidBlaster, it can be upgraded along the way and contains a lot of modules for live recording and broadcasting over the net. Or go for the next hardware step and buy a BlackMagic ATEM TVS or ATEM 1, these are great and easy to operate buy a PC through the included software.

A decklink Quad plus Wirecast would work great.