I'm still looking too. Got a few companies say they are working on some but they never seem to come to market. I just made some DIY steps till something comes to market.
They have cranford ezy climb but reports are they are not very stable. Also Climb Paws but they are a lot more bulky to pack. From what I hear the ameristeps are by far the best. Guess thats why people pay premium for them. I just can't make myself do it, so the search continues.... :?