I think that the SxS single trigger is similar to their o/u trigger group. Dehaan show the single o/u, but not the single SxS. Go to the technical info tab on the left.
http://www.dhshotguns.com/I have 2 Dehaan o/u's (U1E and U4E)and they have both worked great. They are about 5 years old now. It was under $1500 for both guns at the time. I've had one light strike with the U4E. It was in the first box of shells. 2000 shots later it has worked every time. I hunt with the U1E and it has doubled once. I was working the barrel selector to loosen it up and was interupted by a dove. Two barrels at once makes a great pattern! About 5000 shots later and it is still going strong.
I'm a fan.