>canon material
The Fate franchise is pretty big. It started out with the Fate/stay night visual novel that came out in 2004, and since then it's spawned a sequelFate/hollow ataraxia, a prequelFate/zero, several anime/manga adaptions, multiple spin-offs, among other things. Kirei doesn't appear in every Fate thing and has mostly minor roles outside of F/sn and F/zwhich features his younger shorter-haired self, but I'm pretty satisfied with that. A manga adaption of the third route of the F/sn vn actually started publishing quite recently and it's getting a movie adaption as well. That's my favorite route so I'm looking forward to it.
He doesn't appear in F/ha outside of a flashback scene because he's dead. For that reason, I haven't read it yet and at this point I don't know if I'd be able to. But that's a different topic.
>fan works
He gets a good amount of fanart thanks to Fate's popularity. A lot of it is fujoshit stuff, but I don't really mind as long as it's drawn well and he isn't too out of character. There's just as much bad stuff as there is good, but I think that's how it is for everyone. Doujins are about the same. There's some bad and some good. Fortunately for me, the good ones are very good and there's also a surprising amount of them out there, non-h and h. The only downside to that is that very few of them are scanned.
>supporting material and trivia
I guess this is where I'd talk about spin-offs. Fate has a lot of spin-offs including some games, manga series, and crossovers with other Type-moon things. The Kirei's that appear in these are mostly alternate versions of himself with slightly different personality traits but they are Kirei nonetheless. I'm very fond of the Kirei's from Fate/kaleid and Fate/extra
I also know he was in a drama CD for F/z. If he was in any others then I haven't heard them. And for trivia I have his height, weight, birthday, favorite food, and favorite time of the year…? There are some other things I guess I could file under here but they're featured in canon.
>do you create any of your own?
Sometimes. I draw him fairly often but I very rarely feel satisfied with what I drew. I've been drawing him for well over a year now and for some reason I still haven't figured out how to draw him right. I've tried writing before and I don't think I'm too bad at that, but I've never been able to finish anything.