The priming agent makes up such a small percentage of fermentables that you won't be able to taste the difference, especially in a flavorful beer like a wit. I'd use corn sugar.
The Fiesty(sic) Goat Brewery est. 2007 & Clusterfuggle Experimental Ales est. 2009
Planned: sLambic II, Flanders Red II
Primary: Berliner Weisse w/ GB 110 & Brett Brux, Berliner Weisse w/ L. brevis, Dark Mild w/ 002, Dark Mild w/ 028, sLambic I
Secondary: Orange Blossom Mead, Flanders Red I
Kegged: Fat Man Porter w/ 1469, Fat Man Porter w/ 005, Centennial Falcon w/ Conan, Centennial Falcon w/ Denny's, Barrel-aged Fat Man Porter, Belgian Dark Strong
Bottled: Flanders Red I