Structural Engineer to modify the design of a steel structure building

We have a steel structure building that we would like to covert from a single floor to a double floor.
The current shape of the roof is slope, we are looking for an expert structural engineer to modify the slope and strengthen the structure to enable a 2nd floor office. The structural design report of the existing building is attached.
The first floor will have offices, and the typical layout is also attached.
Time is of the essence and we need someone who can handle this as soon as possible.