Hmm, the two middle ones look pretty good to me - similar to actual pterosaurs, which I suppose had a halfway upright posture like what you're trying to do. I don't know how adept they were at walking fully upright/without support from their arms, but they have to at least have been able to stand and go for short distances when needed.
I think the important thing is to make the arms really long and the legs short so they don't have to bend over so much when walking on all fours. Esentially what you have done on the top profile drawing, but maybe make the 'hand' a tad longer. Also keep the back straight and shoulders far back because they need something to balance that big head of theirs.

Speaking of pterosaurs, their wing bone/finger, or whatever you wanna call it, starts at the same place as any other fingers, not at the wrist. Since they have the same basic bone structure as just about any other creature with arms and legs, it looks really weird to me to have that finger so disconnected from the others.

Anyway, if you want some inspiration for this that isn't pterosaurs, look at any type of monkey that does an okay job at walking upright. Gorillas and chimpanzees are always good for reference.