When you said your wife can carry 20lb and you 35lb, is that what your current gear + food and water for the longest stretch you will go without resupply weights?

If that's what your current kits weights, then most likely you could do some tweaks and be pretty happy. If you are over this currently, and/or have the spare cash, I would encourage a first principals rework. I found that carrying less than 25lbs made a significant difference in the energy I had through out the day and the number of miles I could cover went up from when I was carrying 30lbs, and was more than 3x when I carrying the 50-60lb I did when I was younger and stupider.

I would recommend checking out the resources on this site. I have a bunch of notes on backpacking gear you might find useful as you rework your kit.

If you are thinking about doing the AT, you might want to start looking at some of the AT / thru-hike communities like WhiteBlaze, Thru-Hikers, Trail Journals, etc. I have a few links to these sites on my backpacking resources page