if your gym has olympic collars, you can throw those on before the 45's to do extra-wide sumo pulls. You could probably accomplish the same thing by stacking at least 4 5 lbs. plates or cookies on before loading 45's.
I've personally found that ultra-wide sumos are of limited value. As for groin/hip strength, try the "good girl / bad girl" machine.
Zercher squats are a nice lift that can simulate a sumo deadlift also, and you will probably get more range of movement out of the exercise than you'll get with a sumo deadlift.
Play around with your stance, I know it seems to make sense that the wider you go, the lower you'll be and the more power you can produce...however; you might find that your leverages are weaker in wider stances than in narrow.
I pulled sumo for the longest time and started doing more conventional pulls in training and my conventional is stronger than my sumo...just something to keep in mind bro. I hope this helps.