Cougar & Outback are 2 of Keystone's mid-priced trailers, and it's often said [here on the forum] that they offer "more bang for your buck" vs the competitors brands.
It's a buyer's preference, of course, and only you can decide what type or brand of RV suits your families wants/needs.
When doing your research, keep in mind:
In most states, it's illegal to pull/tow anything behind a Travel Trailer; and regulations vary (state by state) for towing behind a 5th wheel. Check your IA state regulations,
and any states that you'd typically travel to.
Also be aware the majority of 5th wheel brands (industry-wide) aren't intended, nor designed, to pull/tow a 2nd trailer (& etc). Most don't have a (receiver) hitch & would
require some type of fabrication..... but, modifying the RV frame typically voids the Manufacturer's Warranty. The majority of RV Manufacturer's now provide an Owners
Manual online, and you can read them (prior to purchase), if it's relevant to you. Here's the current Keystone manual -
Terri, the Chevy co-pilot