Not even remotely qualified to even begin offering advice on how to fit a person to a bike, but I do want to ask a question for clarification. After you set that stem to 25 degrees and stated that it wasn't all that comfortable, could you elaborate a bit? Like maybe it felt a bit cramped? If so, the culprit is likely that stem- as you raise the bars with it, you are also reducing the distance (reach).
I'd say just take it to REI, put it on a set of rollers, and have them eyeball it.