Lattice tower design

Project Description: We need to hire a structural designer for designing a lattice tower. The requirements of the same are mentioned underneath. 1. Height: 150 m 2. Base area: 50 sq.m 3. Plan shape: square or rectangle as per base shape 4. 4 elevator shafts in the center of tower 5. Observation platform for 500 people on top(1 platform accommodating 500 individuals or 2-3 platforms with distributed capacity with a minimal height difference between the platforms) 5. Loads: 500 persons on top, 200 persons elevator capacity, weight of 4 elevators of suitable dimension, observation platform(s) and tower self weight, wind load maximum 80 kmph, other design loads as per guidelines. 6. Material: pipe sections or angle sections keeping in mind the economical aspect. Kindly revert back with other load or functional information required for the design.