I totally agree, I have my 2 Tokays in the Exo-terra glass Terrarium that Double J mentioned (I wanted to Double J!!! darn it!!) I bought the 18"x18"x24" And I don't think anything smaller is approprate for a pair. It's lots of room for 1 though. Too small for more than 2 IMO. I was going to get 4, but they don't make 36"x18"x24" Exo-terra glass terrariums
I still have hopes that they will make them eventually, or you could source out someone to build you one, but that would cost a pretty penny due to costs of glass doors/hinges ect.
They are a good deal also considering they have front doors, vents in the front doors, a built on removable screen top and comes with a styrofoam back wall insert (which my male tokay loves) These Terrariums would be awesome for any aboreal frogs too and other aboreal geckos. Keep in mind a Tokay can get 14" from what I have read, so buy a terrarium that is sized appropriately for how many you want.
I've heard people say that a 10 gal is good for Leos and Fatties also. I do not agree at all with that. As Double J also said they are fine for small 3" species, but nothing larger or they will be cramped IMO also.
To get some ideas marylyn101, take a glance at my Tokay tank on my website. I hope it gives you some ideas