your idea of expanding the Napoleonic range is great. You first sets are 1st class.
I would like to add more weight to what has been written already :
Austrians (Raupenhelm an shako), Russians (in stovepipe shakos) are priorities.
Prussians for Jena-Auertstedt would be great.
Austrians, Russians, Prussians, French for Revolutianary wars would be great.
... and Ottomans would be a real treat. However, I must say Ottomans would be really nice also in multiple poses not just march and advance.
I think with any of these you will have huge success.