About FSDT products, you only need to download the updated Stand-Alone Addon Manager for FS9, which works on the new activation site, after Esellerate closed.
About Cloud9, it's currently not possible to buy or activate Cloud9 products, because Esellerate has closed, and in order to allow products to be sold and activated again, they should signed up with MyCommerce, getting a license for the new activation servers ( which is a separate company ) and move all the existing serial numbers to the new activation server, so they could recognized by it, and of course continue to pay fees for that server. All the things we did for FSDT, basically.
But since they quit the flight sim business in 2009, I'm afraid they won't do any of that, so it's currently not possible to either buy or activate any Cloud9 product after the Esellerate closure.
We asked about this to the former Cloud9 owners, suggesting as a possible solution to make all products automatically activated, but are waiting for a reply.