At first, I had concerns about your scale and was going to chastise Miles2912 for having you drop the monitor out of the diagram (it's a cocktail, so they are in the same plane and the scale is going to be important).
Having seen your revised diagrams, I think that you'll be OK with a single-sider, although you may want to consider going to 3 sides to maximize the verticals. If you stay with one side, you may want to tilt the monitor slightly as in a Joust cocktail -- it makes a big difference not to have to hunch over while playing.
I would plan (to scale, as Miles2912 insisted) the cabinet carefully before building -- cocktails can be tricky.
Have a search for WhammoEd's cocktails as examples and if you want some pics of how the insides of a Joust cocktail are put together, let me know.
Cheers.