26er I'd say yes, go for the 17inch. I am similar in shape and know that we can be in the middle of two ways to go. I'd go medium frame with the smaller wheels.
29ers feel a lot bigger, so you might be inclined to do the small frame if you have a shorter torso.
"Ideal" is relative to too many things. If you can, ride them both and do the comparison that way.
Flip a coin. I am 5'8" and can set up either to fit. If you plan on running bars with sweep like Marys or FU bars, go with the bigger to avoid needing an excessively long stem. I you like straight bars you may be happier with the smaller. You don't actually get much more standover from the 15 because of the top tube sloping up the suspension corrected head tube height anyway.