It's basically an R8... But strangely it appears to be a non-volumetric machine built into an R8 body.
I've never seen one, it was probably one of a few samples built to see if any importers or markets might be interested. Seems the answer was "No".

It's going to be a hand-built machine made to Rocket's quality standards, so yes, it will be a reasonably good machine. If the price is reasonable, it's a reasonable deal.