Actually, 49" is too big. You would be hard pressed to find even a 4-player showcase cabinet with a panel that wide. Most are much narrower (many 4-player games had panels that were under 3 feet).
Showcase cabinets are really common. Go out and find one and measure the panel.
Also, do not angle the joysticks for player 3 and 4, period. It is unnatural, real games don't do it, and it will kill your ability to play 2 player smash TV.