The final product is usually in the Developer/Publisher: sections
Uploaders verifies the official website or the Patreon of the game developers as often as possible to update its thread to the latest version
You can check finished games under the Games category, and then click on "Completed" tag. Shows you all games that are completed or deemed completed, although the overwhelming amount isnt from western developers.
dlsite is the place where finished japanese products like tobihime get put on sale. other than that there aren't really official websites to buy such games from different developers. you have to buy/download them at the developers website (usually blogspot or patreon).