I like how the description of the Nitto moustache bar on the Rivendell site specifically mentions the Nashbar moustache bar, and how they're not the same bar. I've got the Nashbar bar, and they look pretty similar to me outside of the $60 price difference.
I've tried the Nashbar moustache bar on three different bikes now, and I really wanted to love it because it looked so cool. It's a great bar for climbing, but it stretched me out too far on both my MTB and on the utility bike, even with an adjustable stem pointed straight to the sky. It almost stayed on the 'cross bike, except that I decided to try out drop bars, just to see if I was missing anything; and I was, namely the two additional hand positions that drop bars provide. I also found the hoods more comfortable on the drop bars than on the 'stache bars, where they were almost horizontal instead of vertical.
If you want to keep your shifters and brake levers and get a bunch of different hand positions, follow fietsbob's advice and pick up some trekking bars. More expensive but less weird looking (in my opinion) are the Jones bars that canyoneagle mentioned; I'm seriously considering trying out a pair on the MTB, which went back to its riser bar after the 'stache didn't work out. North roads (like the Nitto Albatross, since you've been cruising the Rivendell site) will also allow you to keep your levers and shifters, will provide two riding positions, but will raise you more upright instead of stretch you out like the 'stache bars. If you flip 'em, they look just as cool as 'stache bars, but they aren't as comfortable as when they're mounted with a rise instead of a drop. I have these on my main bike, and you'll have to pry them from my cold, dead hands if you want mine.
The Nashbar 'stache bars, however, you can have if you PM me and arrange to pay for shipping (I'm in Alaska, so shipping will run like $5 or so). I'll even throw in a pair of Tektro road levers that've been gathering dust next to the 'stache bars under my work bench. All you'd have to do is find some bar end shifters and you'd be good to go. My only request would be that if you don't like them, you'll pass them on to some other curious cyclist, or donate them to a bicycle co-op (which I've been meaning to, I just never seem to get down there).