Here's my 2 cents:
(1) Seriously consider
this harness for your cat. Cats can too-easily slip out of (or just plain hate) other ones. So I'd start with that one.
(2) After lots of serious consideration, we bought a class C rather than an A, as well. One of our biggies was STAIRS. We too easily trip over them. My DH actually fell out of a 5th wheel we were looking at a year ago--it was raining and the stairs were wet, and he still slipped and fell off of them in spite of holding onto the hand rail. Took months for all the injuries to heal.
The steps in a class A are usually much more substantial than a 5er, but there's still too many. We bought a C with NO exterior steps at all and it feels much safer to both of us.
While it's nice to have all the basement storage of an A (and you may want to give that a lot of thought, with 3 adults onboard), it's like driving a bus. Class A folks will tell you that "you get used to it" and that may be true, but why, if you don't have to? And there's no way around the ants-under-the-magnifying-glass effect, with the sun inescapably beating down on you through that huge windshield while you drive. There's a reason most class As have fans mounted in the cockpit.
I'm a firm believer that every adult who lives in an RV should be able to drive the rig, because you never know what could happen out there. One day it may be time to move, you have no choice in the matter (for whatever reason), but your husband and son are both sick as dogs, and you aren't.
I'm not the first woman to sit in the captain's chair of a class A and say, No, I'm not doing this. I don't even wanna learn. My DH, who's normally comfortable with driving all sorts of things, just sat there and thought, What was I thinking of?
I'm feeling obligated to point out a few of the negatives of class As, because after this, and on so many other threads, you'll mostly hear all the class A folks telling you all the positives about them. But in the end, everyone will tell you the same thing, which we repeat like a mantra: The Floorplan Is Everything. So if you fall in love with the floorplan of a certain class A, you'll somehow magically learn to live with whatever you thought you didn't like about the vehicle type before you found your One True Love.
P.S. I found
this article to be helpful. It's aimed at people who intend to FT on a limited budget, but I loved the unique way he made his readers consider the details of their intended lifestyle. There are plenty of other which-RV-is-right-for-me? articles out there, and they pretty much give all the same info. This one was different.