How to build an order form for large product library?

I am trying to create a Smartsheet that can record orders for products and the quantity requested for each product via a form. There are over 400 products available, so my original plan of making each product a column name and then the quantity a user would like ordered would be entered in that cell.

Example of original plan:

In the form, there would be a multi-select dropdown for each vendor. When a vendor is selected logic would be in place for the product columns associated with that vendor to display. Then the user would enter the quantity they'd like in the fields for each individual product.

Select Vendor 1 {{ multi-select dropdown }}

Products 1-200 display {{ text fields }}

Form user enters quantity they'd like of each product displayed into text fields.

Now that the column limit has come into play this isn't an option unless we create different sheets for each vendor, but then we can't view all our orders in one place (do reports have a column limit too?).

How have other companies created large order forms for specific products that allow a quantity to be entered for each product? This being a form that doesn't require a Smartsheet login is very important.

Thank you!