Hey neighbor from the OC
The best network connection from building to building is via cable at 1000Mb, 100Mb might be enough depending on the reset of the network usage. If you like to go wireless you should use a N network at 5Ghz.
Here are two capture solutionshttp://www.blackmagic-design.com/products/intensity/
How fast is your internet upload speed?
What file format are you planning on using for streaming?