IMO, since witbier is interpreted so differently by so many pro brewers (Bruery White Orchard, Blue Moon, Hoegaarden, Blanche de Bruxelles, Ommegang Hennepin, Unibroue Blanche de Chambly, and St. Bernardus Wit are all completely different beers), that, at this point, almost any Belgian-style yeast will work for a Witbier, depending on what you are shooting for. For me, I long sought a bone dry witbier with a slight tartness, and so I found my favorite strain for that was Wyeast 3711 French Saison. Lately, I have sought a bit more sweetness and spice and less tartness, so I am back to using the classic Witbier and Forbidden fruit strains (and mashing at 150-152, rather than 148-150). But it really depends on what kind of witbier you want. If the goal is a Hoegaarden Clone, then sticking with the classic wit strain at WLP or Wyeast is preferable. From the sounds of it, you are not concerned with cloning Hoegaarden, and are just looking for a nice Wit with some esters, phenols, and the wonderful viscosity that only raw wheat can provide - I am sure any Belgian-style strain will do fine by you and your palate, if that's the case. That being said, T-58 is one strain I have zero experience with - I have not even tasted a beer made with T-58.