Structural Design For 6 Retail Units

I am putting up a single-storey commercial block that stretches 72-feet along the street and splits into six retail shops. The left bay is 37' × 20', giving three shops about 12.33' wide and 20' deep; the right bay is 35' × 29', giving the other three shops about 11.67' wide and 29' deep. Every unit must enjoy full frontage.

All external and demising walls will be 6-inch concrete block. Above them I want a continuous steel I-section frame and a truss roof system, with 16' 6" clear from finished floor to the underside of the truss. Although utilities are straightforward—no special plumbing or HVAC requirements right now—the structure should anticipate retail loading and let any tenant bolt in a mezzanine slab at roughly mid-height (8-9 ft) without altering the primary frame.

What I need from you is a complete structural package:

• Framing layout showing columns, beams, and truss spacing for both 37' and 35' bays
• Beam, column, and truss sizing calculations that respect typical retail live loads plus future mezzanine loads
• Connection and anchorage details for block walls, steel frame, and the optional mezzanine ledger

Let me know your preferred software and how quickly you can turn preliminary drawings.