I just finished the unwrap and threw on some quick base colors (definitly not final, hehe), and drew some placeholder figures for the back "fins".
lots of work still left. It will be quite the challange to make it seem big when it comes to the texturing.
I chose the 256x512 resolution so that I wont be picked apart in judging by chosing a size thats not compatible with all graphic platforms. That leaves me with 2 128^2 sheets left to play with.
The geometry is around 2800 so far, which leaves me room for another type of skyscraper and some other enviromental stuff. Its a great thing that each sky scraper only takes up 10 tris, so I can add or delete them to match the max requirements, and it wont seem totally out of place.