Fair point on the 1000lb thing (the biggest sumo I can find is in the high 800s), but what's your reasoning behind ROM not being overly important to the deadlift? Genuinely curious.
According to http://primallifter.com/comparing-sumo-and-conventional-deadlifts/ I have a relatively long torso and average arms (along with short legs) so that may be why sumo is far easier for me.
Having said that, I far prefer conventional pulling. I kind of feel like I am cheating with sumo haha.