Since you're a legit player, check out the BG Tradition ligature. Others you could try would be the Brancher or the Olegature (these are opposite ends of the spectrum--the Brancher is more vibrant, and the Olegature is more compressed). The Bonade is also a good bet. All of these will be more vibrant than your Rovner which deadens the vibrations of the mouthpiece too much for my taste. One of my colleagues in the legit world has been using a Fortissimo ligature of late, and swears by it. In a perfect world, I would recommend a Winslow, but unfortunately they aren't made anymore (unless you find one on eBay that fits your mouthpiece).

the bg taditionals are great(just reiterating) and the ultimate ligs work well, thats what i use. they are generall more popular with jazz, but i like it a lot classically. iuse one on both alto and bari