I figured I'd post the few plates that I have that apply to this era. I have more of earlier (especially in the 17th century), if you want me to post them just let me know.
Here's a Mamluk, Bosnian infantryman (I think that a few more local troops would do good... maybe recruitable to anyone who conquers it, including the Ottomans?)
These are cavalry (and mounted infantry) from the 17th century, but I believe that they would still carry over to our time period, especially the Tatar. I also hope you add Kapikulu cavalry.
Janissary junior officers:
Janissary senior officers:
And since you mentioned the shoddy job done for the Mughals, I'll share the ones that apply to this era. Again I have a lot more for the 17th century than 18th, but these are still good I think.
This is from the 17th century, because for whatever reason the Osprey book has no plates from the era of Aurangzeb. But the costumes and armor from Shah Jahan, as seen here, would still basically be applicable I'd think.
The obvious source for the Mughal's heavy cavalry, which I beg you to make recruitable earlier if you mod them. No way should the Mughals be incapable of recruiting cavalry types that had existed for hundreds of years until they researched musket tech (same with the Sipahis, IMHO).
Maratha troops, some of which I'd think should be recruitable by the Mughals. It would make a lot more sense for the Mughals to recruit the Hindu light cavalry (as well as Sikh troops) than Qizalbash, who were Safavid religious warriors.
Finally, I'd like to ask if you'd eventually add some more Tatar units, especially mounted firearmed Tatars, armored Tatar nobles, and musket infantry (or dismountable cavalry). Since the Crimean Tatars really get screwed out of a descent unit list, and the best Ottoman cavalry was Tatar, hopefully you'll consider getting around to it evantually.