According to
this site the Catalina 29rls (2011 model) is 32 feet long, weighs 7684lbs dry, and has a dry hitch weight of 694lbs. That hitch weight will go up by about 300 lbs or so when you are ready to go camping.
I would certainly use a WD hitch to tow that trailer with my truck (a Ram 2500) and so should you with your Expedition. I would get a hitch with at least 1000lb bars or more as your tongue weight is going to be very close to that amount.
I would strongly advise getting a hitch that combines WD and sway control into one unit such as the Reese "Strait Line", the Equal-i-zer, or Blue Ox. There are others also.
I agree with the statement above that the coupler on that trailer will require a 2-5/16 in ball.
Barney