I noticed that you seem to pull with a rounded upper back; a technique I see a lot of other powerlifters use in order to decrease the bar ROM.
Now, far be it from me to tell you how you best pull; but, to my mind, this necessitates that your lower/mid-back will be locked out before your upper back, causing the actual strain of the lift to shift at about mid-thigh range (where you stalled). This makes it easier to pull off the ground, but much harder to lock out. What happens is that your lower back locks out before your hips/upper back, so your spine pretty much has to work in opposition to itself in order to get the weight up.
I see a lot of powerlifters fail their lifts at the lockout, and I don't really think that a ROM decrease of a few inches is worth all the trouble. When I set up to Deadlift, my form is like this guy in the video (skip to 0:40):
This makes the initial pull off the floor a bit harder, but ensures a strong lockout. Tbh, I can't imagine pulling any other way. It's usually the first few inches that are hardest for me; but once I get that sucker up a good 6 inches or so, it's mine. It shifts the focus off of your upper back and keeps it on the legs/lower back.
So what I would recommend is maybe a few test runs with a less-rounded upper back; just to see how you like it. If it doesn't feel right, then good luck with whatever you decide. If your upper back is what you want to work on, Pendlay Rows (DOH at 90 degrees) are probably best.