FYI, the track pictured in the inset is not the same as the standard T-Track found on most production sailboats. Common size is 1 inch or 1.25 inch wide. but larger boats will use even larger size track. There are many, many sizes and styles of metal tracks used on sailboats. Harken, for instance, is a hardware manufacturer that uses a proprietary track design. You won't want that. The common version you've pictured on the boat in the lower picture is what you should stick with... try a google search for sailboat T Track.
The aluminum t track shown on sailboat picture can be found at pretty much any chandlery.. from west marine, defender, MauiPro, Garhaurer, etc...
You can also get information about your boat's hardware by contacting the factory, CatalinaYachts. and talk to customer service. There is also a well known 3rd party vendor called "CatalinaDirect" that can provide related parts.\