Both are limited editions, but I guess the chassis is just a evolution part. Will be the standard (for the alu chassis) I guess. I prefer two separate pieces as well. At the moment I run a carbon chassis, best of both worlds for me.
Most people already have all parts (except the chassis and maybe the shock shafts), but great for a new car to start the upcoming season with. Not for me though. Still going strong with my current one.
Too bad they didn't include rear alu hubs. But I guess that would bump up the price too much.