You could also check out second-hand bookstores or comic conventions. Sometimes, you can find rare or out-of-print comics there. Additionally, you can join comic enthusiast forums or groups to see if anyone is selling or knows where to get the Zero War comic.
To get Zero War comic, you could try looking on popular online comic marketplaces. Another option is to check with specialized comic bookshops that might have it in stock. Also, keep an eye on comic conventions where vendors might sell it.
To get PS1 visual novels, you can start by looking on auction websites. But be careful and check the seller's reputation. You might also consider reaching out to local gaming groups or clubs. They may hold swap meets or know of reliable sources for obtaining these older games. Additionally, some larger game retailers might have a small section dedicated to retro games, so it's worth checking there as well.