A bit of a plot jam?

[kisamehada.livejournal.com]

For this year's NaNo, I've decided to go with something almost purely urban fiction.

I have 4 main characters, A vampire hunter, a young female vampire, a were-raven, and an older male vampire.

The plot centers around the young female vampire, but I was going to write it as four smaller "books", each one from a different mc's pov...book one is the vampire hunter, book two, the were-raven picking up just a bit before where the hunter left off, and then each of the two vampires.

It was a pretty solid idea, but now comes the difficulty.

I'm having a TON of fun writing from the hunter's pov.  He's an interesting character, and has written himself much further into the plot than I had originally pictured him.

So now I almost want to write the entire book from his pov.  And that's the real difficulty. 

If I write it in the four parts like I had initially planned, I know for sure I can get 50k words...probably many many more than that.  But if I use just the hunter, I'm not so sure.  His story is an awesome one, but its not as planned out as the way I had planned to do it.  I am not adverse to the original, in fact it'll be fun to write, and (in my head at least) its a great story...but then there's the hunter who has an awesome one as well...

So my question to you guys is would you go with your original idea, which you know your word count would be safe, or the new one, where word count is questionable?