Seat Options E350/450 Rigs

Hi there. My wife & I do not like the seats in our Ford based Class C. They're so uncomfortable for us nowadays doing even 200mi in a day is rough. 

Standard-ish seat supplemental bottom extra cushion laid on top of the seat isn't cutting it. 

At this point I'd entertain buying seat replacements or some quality supplemental options, just need to hear what people have done or know of.

Thanks much!