It seems that from your original thought of the SAK that you want a small pocket knife that can be opened and closed easily, not a modern pocket clip type folder that may be hard to manipulate, either opening or unlocking to close. What you are looking for is called a one arm man knife. It has a blunted end with a cutout so you can pull the blade open on the edge of your pocket if need be. They look kinda like this....
A pic I got off the web of a Case one hand opener
Just do a quick google search and you'll see several options.

A pic I got off the web of a Case one hand opener

Just do a quick google search and you'll see several options.