Superspies!

So, lately I've been back on the whole "superspy" kick. Watched a couple of my favorite James Bond movies (Craig's Casino Royale and Dalton's The Living Daylights), reading my second Mack Bolan book in a row (I usually read one then switch genres for a while), and dusting off an old story I started writing about another '00' agent, Andrew Hearst, 005.

The 005 story is obviously fanfiction, as it contains references to copyrighted characters and concepts. However, I am toying with the idea of changing those to something original and running with it. My quandary is, do I want to create my own MI6, or do I want to make him a CIA agent? Another option I considered is making up my own, elite organization. Something along the lines of Stony Man from the Mack Bolan universe. I'm leaning towards this third option, as it gives me a lot of creative freedom. The downside is, that it wouldn't be grounded in reality very much, so, outside the Bolanverse crowd, it probably wouldn't get much notice.

Why am I doing this? Why am I allowing myself to be once more distracted by the next "shiny object"? Because that's what I do. I love a wide variety of genres, and when I read any given story, I always wonder if I could write something like that. I know the conventional wisdom is that a fiction writer should limit what he writes to a specific genre (though there is some wiggle room, especially in the science fiction/fantasy realm). Still, a superspy thriller is pretty far from a sword & sorcery epic. Yet, I can't help but wonder which I would be better at. Which one would I enjoy writing more? And yes, which one would be more likely to sell. Again, conventional wisdom says that a real writer isn't concerned with writing "what sells" but is more concerned with finding their true voice. But what's wrong with doing both? Are they mutually exclusive? I don't think so. I'd like to be able to write any genre I like and know that A) I enjoyed writing it, B) I would enjoy reading it, and C) others would enjoy it enough to buy it (hence the "sellable" angle).

Am I rambling? Am I making sense? Does anyone have any advice or thoughts or ideas?