Extension or SAEF?

This is my first foray into EE development so bear with me 😊

I want to open the admin tool (publish & edit screens) to account holders on my website. I want them to be able to manage and edit information regarding properties they have registered with the site. I know I can do this by setting preferences on a per user group basis.

However there are some fields that aren’t available as defaults that I need the user to be able to set and update. For example I want the users to choose their country and then their town based on the country they selected.

Is this the case for an extension? If so can anyone give me some pointers.

OR

Is this the case for a SAEF on the front end that populates the channel entry on the back end?

Thanks for any insights.