Can't give you an opinion on the different pass thru's, but if the Alaskan is a popup, on all 4 sides, you'll face the same challenge I did at the start. How do you get the hard popup piece to either pop out or fit under/over/thru the lifting panel? A number of the pass thrus are fairly high on the Fuso cab. Short of a set of doors in the camper you open/close on lowering, or a rolling door style arrangement, or have it high enough that the lifting portion is above where the pass thru is, how do you make the join between between the lower portion of the camper and lifting section?. It's something you'd need to solve for.
I spent much brainpower on it early on in the piece but couldn't come up with an arrangement I was happy with. So I put my spares between the cab and body, did away with the idea and moved onto the next thing.