Ideally I wanted the grid to be a perspective projection rather than isometric as there would be 1st person elements in it later.
What do you mean, 1st person elements in the background of your grid?
If so, then you could use a second view that is ISOMETRIC to draw your grid without painting a background color using NOSKY. Then just put the view on top (layer > 0) of the camera view and you are done!
