If you are already have visual data such as a basemap and just need to select features the WFS would work very well for that. Although, if you need a visual component to go along with your selection, you would be better served by a WMS service, since it was created for that.
Although hearing your use-case as you described it, I would personally would just use a WMS service.
Also, the GeoServer Blog as a great write-up on the two services and when you should should leverage them.
Edit: On an additional note if you are doing anything other than simply querying the feature data, I as a general rule just use WFS, it excels when it comes to data manipulation in comparison to the other OGC services I have used lately. Also, take that with a grain of salt, that is just what I had experienced in my use of the services, which is why I have attached the preceding and following links.