Hello, go for Wagonr because as you said it should have a tall seating, wagonr is among the best.
I agree with you on Nano, as it is very easy to drive and the best to go around in the city with good FE and interior space.
My last suggestion would be Ritz if you can shell out some extra bucks because MAN! this car has got some space and comfort. And as it is Maruti, you get the lowest maintenance through out the segment. FE is an issue here, as the car is big it will give you around 14 kmpl