Hey Scott,
I'm with you in thinking a good sized comfortable bed
is a necessary thing after a day out in the fresh air, most
probably exerting yourself much more than usual.
As far as the step-ups go, maybe it's just a personal
idiosyncracy of mine, but I think an exterior mounted step - fixed
or swivel up for travel clearance for a side mount, or maybe one
rear mounted and attached to a step-depth rear bumper-step,
would be a good idea both for practical use and convenience, but
I also think it would be an additional feature that'd set your kits
apart and show that you are thinking beyond the usual [as if the
kits themselves weren't evidence enough already !].
Here's a fast Paint drawing of a couple possible basic designs.
[I'm sure there are many other possible approaches for them.]:
Click on the pic to make larger:

Cheers,
Norm/mezmo
If you have a house - you have a hobby.