Interfacing SoCs with the cRIO

[yash101]

Hi guys,
I am thinking about onboard vision processing on the robot, on something like a RPi or an oDroid. To impress my team enough to the point that they want onboard tracking would mean that I get the process done as easy as possible and as fast as possible. The main complexities of this system would be:
Connecting to the cRIO the easiest way possible
Powering the SoC and shutting it down safely

The main thing that I am worrying about is connecting to the cRIO. What do y'all say? i2C, UART, USB => RS232 => UART, SPI, DIO, Network, NetworkTables? Which is easiest to implement on the cRIO? Which is the most robust?

I am currently convinced that i2C would be the best bet because it is hardwired and there is already a port on the cRIO. Network Tables would possibly be a little slow. What do you guys think?