Using the Flanders Handlbars site (below), you can closely compare the Height, Width, Pullback, Center, Clamp Area measurements with the valk bars. (Remember the IS bars are a quarter inch narrower than std/tourer bars (1/8" each side)). And the valk OE risers are 3 1/8" tall, or whatever you have on your bike.
I went thru this years back trying to get a better handlebar (and riser) fit, but quit. As I recall a couple of the Harley bars (Heritage and road King) were close enough to be worth looking at. Do not forget to factor in your risers (or proposed risers) together with the handlebar dimensions when trying to determine where you want your hands (as well as the possibility of having to change some cables/hoses)
http://www.sideroadcycles.com/AmericanMotorcycles/Handlebars/Stock_Bars.htmlModel Honda Description Year Bar Diameter Height Width Pullback Center Clamp Area Factory #
GL 1500 C Valkyrie 1997 - 2003 1" 6" 33" 14" 9" 3" x 5" 53100-MZ0-000