It's awesome to have two completely identical FRC legal robots and control systems.
One alternative is to use a lower cost micro controller to get a low cost practice robot up and running for driver practice and other testing.
There are many great options these days.
Our own Arduino based Gorgon Controller is low-cost and can handle a complete robot, including pneumatics.
http://www.andymark.com/Gorgon-Ether...-p/am-2900.htm
The CTRE Hero is also a great option, especially since it natively supports the STX.
Real roboticists interact with and experience a multitude of hardware and software platforms in the real-world. The RoboRIO is highly specialized...so building around other popular alternatives is also a great way to expand your program and it's educational opportunities.