We do sell the amplifiers from our WorxAudio lineup as a separate rack-mountable unit but we do not sell them direct to the public.
You will need to contact a Presonus authorized dealer to purchase them. If you are not certain where to find an authorized PreSonus Commercial dealer please email us at Sales@presonus.com with contact information and we can help you find someone.
Specifications and details can be found here. http://commercial.presonus.com/products/WorxAudio-PDA-1000R
This is a single input dual channel amplifier, with an output of either 2 channels at 500W RMS or 1 channel at 1000W RMS (bridged).