By saying the rpg idea is gonna die here on the blog, you're setting yourself up for failure! Delete that line from your post or at least from your heart.
Run with it!
Some quick thoughts:
Fiasco is pretty hard. Really more improv than rpg, so totally not a system for most people. I'd say the best thing to gleam from it is the "playset" feature. Come up with a solid system underneath, then you can plug in your "When Cthulhu Cthalls" playset/deck/dice/module. Next time, it can be the "Dungeon Crawl" set.
DCC: I wish we had played more. I felt like there were too many people to successfully pull off an online sesh with that game. I forget - is it made to be played with a tons of dudes? I also don't remember how much player-input there was when it came to "telling the story". Wasn't Jawn a DM for that?