With ACE and Vista you are looking at the lightweight model lines from those two manufacturers. Big tanks, higher floors for more underfloor storage, are not part of lightweight design.
Winnebago's entry line full-size A gasser is still the Sightseer, which has 70-80 gallon FW tanks (80 in the 31-foot 30A) and 90 to 100 gallons combined waste tank capacity. Sightseers are now built on 22,000 pound chassis, has the capacity to carry the weight of that water.
Looking used, I would look at Sightseer, the models, trim, capacities, and market position have changed little over the past ten years, except to move a little upscale from when it was the entry-price line. Vista was recently slipped into the line as Sightseer got too expensive to compete with low price models in other brands.
Vistas are built on 16,000 to 18,000 pound chassis, until you get up to the 35-36 foot models. Then you get larger tanks. Even a lightweight has to get heavy when it gets too big.
I haven't bothered to figure out Thor's current market position for each of the model names they still use, but back when they were separate brands, Damon's entry-level Daybreak was a relatively full-size coach in the 30-32 foot size, but Intruder was even heavier with more tanks and storage, but maybe starting at 34 foot. Thor's FourWinds brand had a lightweight Hurricane and a heavier Windsport, with similar floorplans in the smaller (32-34 foot sizes) but Windsport was the one that got higher GVWR chassis, bigger basement storage, bigger tanks and options like 50-amp electrical and 5.5 KW generators.
Coachmen's Mirada was also built in the Hurricane class, you would want to look at least one model line above that. Depending on model year, Coachmen has produced as many as four price levels of A gasser.
Looking at old Bounders (or Flairs or Southwind Storms) you are looking at Fleetwood's mid-range, full-size lines. Find an old 26-30 foot Terra/Fiesta, and you will see something more like today's ACE or Vista.