I'd go for the BabyHawk Oh Snap as well -- I agree that Becos tend to fit smaller to medium sized mamas better, and if you have broad shoulders, I don't think it's going to be the best fit for you. I get a lot of broader/taller/bigger-chested mamas who find the Beco too constricting through the shoulders, although the newer designs are definitely better than the older ones in this regard. If you do decide to try a Beco, go for one of the 2010 designs.
Quite honestly, your dh may have problems with just about any soft structured carrier -- I think the BabyHawk is a better bet for him in terms of potential fit, but it's not guaranteed. You'll just have to try it and see -- a lot of really big guys have better luck with non-structured two-shouldered carriers such as mei tais.