3D Product Concept CAD Model

I want modelling for a suitcase so that i can make custom design changes to it to present to a customer. The goal is purely conceptual: I want to see form, proportions, and overall look without the burden of full manufacturing dimensions or tolerance data.

Your task is limited to 3D modelling; no 2D drafting or photorealistic rendering is required at this stage. Feel free to work in SolidWorks, Fusion 360, Rhino, or any comparable parametric modeller you’re comfortable with—as long as the native file and a neutral format (STEP or STL) come back to me for future revisions.

I’m looking for:
• A single, well-organised 3D CAD file that captures the product’s external geometry.
• A few viewport screenshots or a lightweight viewer file so I can quickly review angles without specialised software.

If you have suggestions that sharpen the concept or improve ergonomics, I’m keen to hear them before you lock the file. Turnaround within a week would be ideal, but let me know if you need a bit more time to polish the model.