Buyers should prioritize Cold-Rolled Steel (SPCC) for the main structure due to its superior load-bearing capacity and surface smoothness. The thickness of the upright columns should be at least 1.5mm to 2.0mm, while shelves should be 0.6mm to 0.8mm to prevent sagging under the weight of liquid medications. Ensure the surface treatment uses Electrostatic Powder Coating, which provides anti-corrosion, anti-bacterial properties, and resistance to chemical spills common in pharmaceutical environments.