I have not gone and looked at the trucks in question here, but there is no"take the top off" to a condo.  If there is something to take off at the top they must just be raised roof sleepers instead of condo. 

edit:  Now I have gone to Taylor and Martin and looked.  The Farmalls which I think are walmart trucks   are not condos.  They are mid roof and the top fairing will come off, making them about 10' 6" tall.  

The Freightliner, on the other hand, is a condo, and it's just gonna stay tall.