Experience with Belgian candi syrup?
Belgian Candi Syrup
My preference if I was brewing a Dubbel would be to use home made dark invert sugar, which I've made before when brewing mild and amber beers. For an Enkel you wouldn't want to use a lot of sugar anyway; I brewed one recently and only used a small amount of golden cane sugar so didn't bother to invert it. And for a Tripel I've used about 12% home made pale invert sugar.