Roses are mainly used in cooking in the form of rosewater. Rosewater--as with rose essential oils, attars, absolutes, and concretes--is typically (or at least commercially) made from the same rose varieties, which are the centifolias and the damasks.
I am not sure what you mean by "less of a floral scent and more a sweeter" aroma. I have occasionally smelled flowers that, to me, seemed to have a "sugary" or candylike scent. I have one iris like that. (The scent of iris flowers notoriously cannot be preserved. I have never tried this myself, but one of my friends tells me that attempts to extract the fragrance from iris flowers by any and all means, results in something that smells like old girdles.)
I am tempted to suggest that you try using other flowers, like violets--but flowers are inherently going to smell floral.
If you want a sweet (sugary?) aroma for cooking, I think maybe what you are after is the smell of carmelized sugar.