Sad to see this end. I was quite happily lurking around...
...but happy to see you interested in continuing as another nation!

I throw my hat in favor of France.
Liberté, Egalité, Fraternité, and let's freshen her maiden fields with perfidious Anglo blood!
Game-wise, she is the most interesting. There's the all-out war with Great Britain going on, countless colonies to claim, a (presumably) shattered economy to recover; and then there's the collision course with your own Übergroßdeutschland*, etc., etc. You'll have a lot of things to keep you occupied for much longer than Prussia's fifteen years' rise to the stars.
*Yes, I know, that's horrible, horrible German.