High Speed Controller/Data logger... HELP!

The timing is looking a bit marginal in several respects.

About 20% of your time will be taken up just by those analog reads.

I don't know what format you plan to use when you send the measurements to the PC, but you will need a high speed on the serial port and a very concise format to achieve 1KHz updates.

You don't mention the control algorithm so I assume it will be simple - as long as it is, that remaining 80% of the CPU time should be ample.