At 5'7" Definitely go with stock length
I'm a tad over 6'; not quite 6'1", and I have the Accutronix extended forward controls. I have around a 34 inseam. the stock pedals were an inch or so too close, but the extended are a little too far for where I'd exactly like them. The footpeg part is fine, but toe-ing the rear brake I find I have to shift slightly forward, to where the muscle movement is coming somewhat from the calf, as opposed to just forward/downward with the foot. It's quite doable, but I find myself constantly wishing I could get the things an inch closer to me at the base. (I've adjusted the arm up along the splines as far as I can to bring it closer, but there's limits to how close you can bring it.)
Alternatively, I'd suggest considering Raw's adjustable set. They adjust fully at the base 1-3", as well as along the circular spline thingy's, so are truly adjustable. And yah, I like Troy's styling's better too, but Raw's don't look bad and that adjustability will start to look really good if you find you've got a non-adjustable set you just can't quite get in the right position.
Wish to hell someone would fabricate a forward control relocator plate or something that'd let you move them around a bit ...