I'm sorry to hear you had to sell it, but you must be a good friend to do that! It was looking great.
My opinion is, don't build the helmet for what others want, or what the norm is, and don't build a helmet just because it's not commonly built. Pick the one you like the most, and you think is the most awesome, because at the end of the day it's you who matters most! And... you who has to look at all day while you work on it!
Everyone's done an ODST helmet, but that's always been my favorite helmet hands down, so I picked it!
The best part is, though... that you can make both! It's not that hard or expensive a hobby that you can only do one! So do your favorite first, and second can come later. And you've shown your work to be fantastic, so it'll be awesome for sure.