Hi George,
A couple years ago my mother bought a Trek 7100 or similar (step-through upright/comfort hybrid). I didn't really think anything of it (positive or negative), other than, oh, that's a decent upright/comfort hybrid for her that she can ride around the neighborhood.
And then one day I tried to ride it. I nearly died. It came/comes with a very short, very "puffy" saddle (although not soft -- you don't really sink down on the saddle), with very short rails. So it pushes the rider quite forward, toward the bars, and then puts weight on the rider's hands/arms. And because it's so darn short, with short rails, there's nothing you can do about it. You can't move it, or you, backwards to get the weight off your arms.
Anyway, went to the local Trek store (that's all there is here) and found a relatively wide saddle with longer rails. It's from Bontrager, but don't know what model (but it wasn't expensive). It's actually quite wide -- it's probably 168mm at the widest part of the saddle -- and it's not at all "puffy", but it's really quite comfortable to ride. (It has a center cut-out, but given the riding position it doesn't seem necessary!) My mother loves riding her bike now. (And I can ride it and not think, "good lord! What sadist designed this bicycle??")
So, that's my advice -- find something kind of standard but wide enough to sit *on*, with long enough rails to move the saddle back and forth.
Good luck!
Liz Sherwood
Washington, DC (thought currently in the Palm Springs area, where my mother's bike is... :-) )