A cocktail cabinet can take up more space, especially with CPs on 3 sides:
Upright
32" deep x 28" wide footprint (just guesstimating)
Add 18" to depth for players standing (or stooling) in front (another guesstimate)
Total depth = 50"
Width = 28"
Total square inches = 1,400 (9.72 square feet)
Cocktail with only 2 CP, one on each end
24" deep x 36" wide (just guesstimating)
Add 18" to width for players sitting on each end (18" x 2=36")
Total width = 72"
Depth = 24"
Total square inches = 1,728 (12 square feet)
Cocktail with 3 CP, one on each end plus one on wide side
24" deep x 36" wide (just guesstimating)
Add 18" to width for each player sitting on each end (18" x 2=36")
Add 18" to depth for players sitting at wide side CP
Total width = 72"
Depth = 42"
Total square inches = 3,024 (21 square feet, twice the upright!)
These are only rough numbers since they will vary depending on the number and size of people playing at any one time. It can be deceptive, an upright catches your eye and looks huge while a floor space eating cocktail can be hidden under a tablecloth.
As for the screen appearance are you going with a tube or an LCD? I built mine with a tube, if I was building again I would build with an LCD (they were still high $$$ when I built mine). The tube looks fine from all three sides but I would love the shallow and lightweight LCD for the option of building in a tipping top/screen hinged on the 3rd panel side (that would need another thread, sorry to distract).
If the cocktail will be your only cabinet then I'd say build the 3rd CP so you can enjoy more games. I went module on my 3rd CP but just leave it on all the time out of laziness

Z