Thanks for posting.
FileMaker Go has the ability to sort by multiple fields. To do this, tap on the small magnifying glass in the lower right hand corner when viewing your database and choose Sort Records. In the list of fields that comes up, tap on column C and then column A. From here, click Apply and verify that everything sorted as expected.
When setting up your database using FileMaker, you can create two table occurrences (boxes in manage | database | relationships), to the same table. If you create two layouts, one to each table occurrence box (selected in Show Records From), you can have one set of records on one layout and a different set of records on the other. This might be a way to get what you want when you described "saving a sort order as a layout".
It sounds to me like you'd like the layout to automatically apply your sort whenever someone views it. If that is true, create a script that runs your Sort (without showing the sort dialog), then attach that script as a Layout Script Trigger for the On Layout Enter event.