I need to implement a dialog for a web application (ASP.NET/C#) where users can search and select one or more clients from the company’s database.
Actually an existing version is already used (see attached image) and I have to replace it with a new version (it comes from an external legacy software and will be dismissed).
The goal is to provide an intuitive and easy to use GUI, still providing the basic functionalities like: search for a client and add it or remove previously inserted.
My idea would be to develop the dialog with jQuery Dialog plugin and using web methods and Ajax/JSON to interact with them for interacting with the server and the DB. I cannot find a good solution yet for the contacts list, since I would avoid using GridViews or tables, if possible, for listing them.
Does anyone knows if further plugins or best patters exist for develop this UI and its functionalities?

Thanks for the hint, indeed for the search I also thought to a autocomplete for make the search easier.
My bigger concerns were about the Add and Remove selected Clients in a “modern” fashion.
I found this MultiSelect plugin that works perfectly for my needs (and maybe it could be useful for yours as well).
Not only it let use Multiselect to add/remove entries, but also have some auto-filtering capabilities when searching the entries. I will try to add this to my solution.