Have you considered bartop designs? Bartops are naturally upright but have a relatively low profile.
Also, have you factored in glare? Your room gets a lot of light for most of the year. A cocktail, with a flat screen, might be unplayable in that environment. A bartop, with a more upright and slightly sheltered screen, will have much less glare. At the very least you can turn it away from the sun/reflections.
Bartops also take up less room and are easier to move than cocktails. If you make two, you could network them for multiplayer games, and you will both get plenty of elbow room
