I would recommend the Marathas. I'm a quarter-way into a campaign with them, and it's a good position. Two territories, with two easily snarfed within, one major opponent (the Mughals). Sure, you have to take Portugal's port, but they get over it (in my campaign by becoming dead). Yes, they're allied with the Brits, but the English don't really care, and will drop their war with you the first time you send them a tea set.