Answering the original question, as well as the Middleburn DUO, there is also the FSA 386. There are a few other more obscure ones as well. KCNC I think do a double?
A lot of the very fasted people in the world have been running single 38s or 36s so losing a 44 is no big deal. A lot depends on your pedalling style, but I like to spin rather than grunt. Having said that, if I fail on a climb it's probably more to do with lack of fitness and technical ability than gearing. In other words, lower gears wouldn't have helped.
I'm running 32-22 and I'm under geared and will up it when it wears. I'm running a lightweight bash for protection, the bash has actually taken a battering. I have no problems running without, looks fine IMHO, just a bash is better for that bike.