Yeah you'll have to make your own isometric graphics and new not-gay characters as well as find the scripts for the supporting movements.
They do exist and are certainly available. Though you may have to join a few communities to get them.
EDIT: I've done some research and the isometry you're looking for might not be easily obtained. If you would settle for a more strict isometric view like this...
...you won't have to waste that many tiles and the sprites/graphics would be a lot easier to make. The top down 8-way movement scripts and graphics are abundant so no worries there if you choose this style.
...and yes, that is a screenshot of Nox. Awesome game.