I've never personally used the Exo-Terra terrariums so I don't really know how much ventilation they have....but everything i've ever read about chameleons says that they need an enclosure with a lot of ventilation, hence the screen cages.
Is this your first chameleon? If so, I think you might want to strongly consider going with the Veiled as they tend to be hardier, more tolerant chams of the three you mentioned. Panthers are good too, but much more expensive than the veileds. Jackson's tend to be the most difficult to keep of the three.