I like to putt with an arced stroke, although I usually recommend that golfers try to keep the stroke *almost* straight back and straight thru as those who try to arc the stroke seem to overdo it.
I've gotten questions in the past as to what putters are best for the Straight Back Straight Thru stroke and usually I answer with the long putter. Just came across the Dandy Putter which *claims* they can fit it for somebody who wants to use the SBST stroke.
Here's a video on the Dandy Putter (http://www.dandygolf.com/DandyStory.wmv). Of course, you can learn more by going to their Web site at www.dandygolf.com