How can I collect information on all the MTG decks that have ever been played in standard/type 2?
All Standard MTG decks will be hard, but I assume you're mostly interested in the most successful ones. In that case, I'd start with the Event Archive on Wizards' website. Especially for older events, the format isn't always shown in the list, but a few clicks will be enough to determine the format.

Now, for example, let's take the 2000 Pro Tour Chicago. Scrolling down the coverage article, you'll get to the Top 8 Decks page, which shows you the archetypes which were successful back then:


White Rebels
Red/Green Aggro
White/Blue Rebel Control
Blue Control (Rising Waters)


(not sure about the names, though)