Truth? Halfway through your post I was so stunned by awesomeness to forgot you were talking about something not already written and was on my way to Amazon already to buy this.
IT SOUNDS *THAT* AWESOME.

I vote for Napoleonic tech. It feels fitting, cos you've got to have the significant tech advantage to do srs Imperialism. This is only slightly because I just read all five Temeraire books in a week. (Are you aware of the Sharpe series? Lots of Napoleonic gun action in that - and Sean Bean!)

Also? GO DO YOUR HOMEWORK.