The tank could work with blue tongue skinks, would be tight. I always recommend a 4 foot tank with them. You could definitely do a very nice leopard gecko tank. If you go with a tree dwelling species of lizard you could add live plants and utilize the height of your tank.
I would not recommend an ackie's monitor for your tank. I believe the bare minimum for them is a floor space of 8 square feet. I also find chameleons more fragile, especially if this person is getting his first lizard, I would not recommend it.
To the O.P. are you looking for something you can hold or just something to look at? Tokay geckos can be a nice animal to own, I used to have a few.