Supply on the OneHot mounts is really hit-or-miss. I found my on AuctionArms, I believe, for $69 + shipping.
For what it's worth, I have both the Ashley/XS scout mount for the 2A and the OneHot mount. Each has its stengths and weaknesses. The Ashley mount is much, MUCH easier to install but requires that the lower forearm stock be inletted for the mount and the upper forearm stock be discarded. The OneHot mount fits perfectly in the old rear sight mount position so you can retain the stock look of the rifle, but it's quite nerve-racking to get installed and you'll likely do some minor damage to it getting it pounded on.
You use heat to expand the OneHot mount and then pound it on in place of the old rear sight mount. Seemed like no matter how much heat I used, it DID NOT want to fully seat. Of course, when it finally DID seat fully, it was also crooked. :banghead: It took many hours and more than a handful of choice words to get everything to reasonably line up.
I have an extra Ashley mount - if you're interested in trying that, drop me a PM.