The closest thing at present for sale, is the KOM Cycling F-A option at $350 USD
Notably, that includes two full-sized decks along with the F-A motion parts. So at a price of just $50 difference, the KOM device has a fair bit more to it depending on your point of view.
Honestly, the general trend in the DIY side of motion training has been a focus on the leaning action first, and the fore-aft action second. As such, there are more examples and options of the rocking action on it’s own than F-A motion on it’s own. But considering the motion itself, doing a pure F-A DIY could be done will relative ease and low cost, at least in some ways I can imagine.
Maybe this new Neo option will spark some of those options, especially for those that have a preference of F-A motion vs leaning.