You should buy a Canon C200.
It has a long battery life, affordable external power solutions, and long duration recording via dual SD card slots.
It has both an SDI and HDMI output so it'll work great with high end or low budget streaming kits.
Notable accessory: The USB 3.0 capture devices from Magewell are amazing tools for small footprint streaming setups.
They are driverless and have wide compatibility unlike similar capture devices from Blackmagic.