It is possible to add a column to your database that stores the lowercase version of your value, and then sort on that. For example, if you were listing businesses, you would store two values for each record:
- FedEx, fedex
- FDA, fda
- Florida Oranges, florida oranges
Then you can display the first column in your site but sort by the second column.
This is not very elegant though. Wix should support this.