Butterfly (or trekking) bars seem to work best on bikes with longer top tubes (or longer for your size), because they bring the hand position closer to you. They are nice because of the large number of hand positions, and more places to put stuff like bike computer and GPS. I have used Titec MTB bar end extensions to mount Third Eye bar end mirrors, for example:

http://www.crazyguyonabike.com/doc/p...?pic_id=281733

I converted my new Rocky Mountain Sherpa to trekking bars when I purchased it (originally had drop bars). I thought I would prefer this setup, but I found that when I compared this to my Co-Motion Americano, which has drops, I preferred the drop bar setup for big climbs. The two bikes are sized differently, so it's hard to pin this completely on the handlebars, but somehow I found that I felt more tired with the trekking bars. Perhaps it's because the position is closer, and thus more upright. Also, I think my Sherpa is a bit too short in the top tube for trekking bars - I felt like I wanted a longer stem, but it's hard to find stems much longer than 120mm nowadays. I tried a 150mm Softride suspension stem, but that stem introduces other limitations due to the movement of the suspension. Point being, it's not a slam dunk - for any particular bike, the fit will be different and you may need to experiment to see what bar setup works best for you. Also, be prepared to try different stems - small differences in length and angle can make a big difference to your riding comfort.

If you go with trekking bars, then I have found the SRAM 1:1 Gripshift shifters work well there. I was even able to mount these on my drop-bar Americano, by using some hacked Titec MTB bar end extensions which I had filed down on the inside of the clamps to make them fit the wider diameter road drop bars. This setup seems to work very well so far - see this thread for a description:

http://www.crazyguyonabike.com/forum...read_id=185783

Overall I think handlebars are a personal preference, just like saddles. There's no one right or wrong choice, it's just whatever feels best for you. So experiment and play around with it - and make sure to include some nice big long hills in your test rides, as I have found that cranking a steep hill for an hour tends to bring out the differences more starkly than just going down the road and back.

Neil