I'm speaking about these cards .

The one where the Rules are written (there is one for "Runner actions", and one for "Corp actions"), and the one to indicate how many clicks I have used in the current turn.

I would like to find some shop online where to order them. Does such a shop exist? I couldn't find one.

I have 4 decks at the moment, and I'm hoping to build at least one for each faction. I don't like to have only one of these "special cards", because I'm always looking for them: "are they with this deck? No this one? Oh no, they're in the box somewhere...****." Plus, if I lose them someday, where can I get new ones?

For retail sale, they're only included as 1x cards in the core set. Each of the decks in the Store Demo Kits that game stores can get from FFG has one rules card and one click tracker card, but I don't know if your FLGS would let you plunder their demo materials for your own private use. Besides, that route is not available for everyone and wouldn't be fair to the other people who thought about it later than you did.

My first suggestion is to put the cards in some distingushing card sleeve that makes it easy to find, even such as a hard plastic toploader.

My second suggestion is to do what I'd venture to say most people do: memorize the rules, find some other way to track your clicks, and don't worry about cards that are basically included as the equivalent of training wheels unless you're teaching someone who would get use out of them.

I put my Corp Identities in Purple Sleeves with the Corp Actions and Corp Click Tracker cards. I put my Runner Identities in Green Sleeves with the Runner Actions and Runner Click Tracker cards.

I find that other players don't bother with these cards, so you can probably get them from your fellow Netrunner players.

I find them useful as a place for storing my Unspent Clicks and Credits.

After one or two times of playing you should have those quick rules memorized. That's a good suggestion by etherial though. Just ask you fellow Netrunner players. I have multiples from multiple core sets. I would happily give them out if I were asked.