It would be very hard to pin down the equivalency details of construction products. Nearly every item is slightly different from each other, so there will always be a point of argument.
If you looked at insulation only. In 150mm quilt, you could have glass fibre, sheepwool, non-itch manmades, different, lengths, densities and U-values to pick a few details.
Even blocks- different strength characteristics can exist from one manufacturer to another in the same class of block or brick.
As more and more tenders are being 'qualified' with alternative products to those specified, it would be a great resource - the service you're offering, but it would be a minefield. I'd say most 'other manufacturers' would challenge your equivalency criteria.
But a great idea - web searches for brand products would bring your website up front promoting the alternatives!