Wingflex, 21st Century probably isn't the greatest tower block. A lot of the F/O accommodation is in Al Barsha which is a bit away from the city centre but very handy for Mall of the Emirates. Also good for the restaurants/beaches at the Marina.
Most of the apartments for F/Os, wherever they may be, have windows that open and balconies. However, you get what you are given and if you happen to end up with welded shut windows, though!
My suggestion, take the allowance and rent a nice big one bed apartment for about 55,000 a year. Or a two bed for about 75,000. You can keep the change.