I find it remarkable how "passenger foot well room" is so much of an issue that you would rule out the most capable, most affordable, most reliable, most serviceable, and most popular E350/E450 chassis in the RV industry. I too admit the foot wells on both driver & passenger side of the E-series chassis are not impressive, but after our first day or two, it's out-of-mind.
Specifically about the passenger seat, in our E350, it adjusts quite far back, so much that it is easy to place your left leg to the side for a very comfortable alternative position.
At the risk of sounding crude and insensitive, "get over it". Don't limit yourself to the least popular chassis types, especially with the "used" RV market. Focus instead on the "construction quality" of the house with consideration to your desired floor plan. You'll get a much better value and selection if you include the E350 or E450 in your search. You may still find the "ideal" rig on the "ideal" chassis, but you owe it to yourself not to rule out the majority of used motor homes.
