a-z index plugin with multi-column names list for search query

i am looking for a way to solve the following problem:
first, you should see the letters of the alphabet listed horizontally. on clicking on one of the letters, a multiple column window should open below and contain a list of names beginning with the chosen letter. the names should also be klickable and should produce a search results list below the window with all the posts containing that klicked name (preferably without reloading the page).

how could this be done? is there a plugin for that?
thanks for your help!