I got the Devantech USB-I2C and the MD23 Motor Controllers here. While I'm trying to get the software straightened out, I'm getting them mounted and cable assemblies made up.

The FT232R was recognized by linux right off, next is to figure out how to communicate with it.

So the sonars, motor/encoder/drivetrain, EFIKA are mounted and in-place. We almost have a functional robot!