would the sumo be best since my legs are stronger than low back?
If you're looking to utilize your quad strength -- nope. You'll use your quads way more with a close stance.
I always have a problem with term quad-dominant. 99% of the people who use the term are not actually quad dominant, they are hamstring-weak. If your quads are "dominant", work on your hamstrings. Don't look for a way to lift around them. Hit them hard.
-from Joe Schillero's recent article in Elitefts
Pull using both. See which one works best. Don't worry about the term usage and whether or not it applies. Just pull and see what happens....then make a decision.
Most pulling if not all will build the hamstrings. Squatting w/o a box will help the quads. Squatting + deadlifting = strong back and legs. Don't overcomplicate it.
Well I have no idea what your level of lifting is but if you aren't already then add Romanian Deadlifts to your routine.
They will build strength in your hamstrings, glutes and erector spinae as well as teach you how to engage your lower back.
This will have an impact on your squatting as well. Staying tight will make all your big lifts go up.
Make sure you do them controlled. Don't round your back to lift more weight. That's just dumb. Stay tight and thrust your hips through.