Everything on your list is an E-450 chassis but you are only looking for a 24' C. Take a good look for an E-350 which in the size you seek offers a number of benefits...
The E-350 will give you a smoother/softer ride and better mileage. You will have more power available as the 350 has the same engine and trans as the 450 but is hauling 2,000 to 3,000# less weight which is something to consider since you want to tow your boat. In a Class C larger than 25' I would probably go with the 450 but 25' and under an E-450 is simply overkill.
There aren't many out there but take a look at the Nexus 23P which is 24' 6" nose to tail. Happily, ours came with the 55-gallon fuel tank vs the standard 40 so we have excellent range in a very well built, great layout coach. I'm not a fan of slides, especially if they have to be deployed to use the coach... as in sleeping, cooking, bathroom usage etc., but like the man said: "Opinions vary". Good luck.
:C