Mac Thunderbolt
 

I was looking to use a Mac Mini or Imac to play out 2 channels of video not at the same time but one channel straight after the next as in a live broadcast were I might swap from commercials to a moving sponsor banner. What I was wondering is if I had 2 thunderbolt ports will this allow me to have 2 channels of video output. Or would I need to go to a mac pro desktop with a black magic card or a mac pro laptop.
Thanks for any advice.