Thanks for your suggestion. We have an open enhancement request to support dynamic choice lists that can be updated from an external source. I've added your comments to this request and will endeavour to keep this thread updated with any progress.
You already got a request! That's a good news. Hope it will be available soon. I have a comment for this request. I would like to show the values in the list from multiple fields. The database I'm using has two fields for name; one for first name and the other one for last name. To select one data from the list, users need to see whole name.