There is one by that name showing currently. It's owned by Hucklebug/Rachel Howell.
I post under my initials now, but yup, Sin City is my boy and I am in Virginia. There's another one that also has an established show record but it's out in California. I don't think there's anything wrong with reusing a name, particularly if it's going to be in a different discipline/division/level/geographic area.
I do, however, really like some of the names mentioned. Silvia is adorable. I love the one word names. My other current show horse is named "Sentimental" and we call her "Stella"....had I thought of Silvia I might have called her that--great name!
I've really wanted to name a horse "Stiletto" but Cara Flynn used it a while back--but I don't think that horse is still showing under that name. That's a nice sultry name for a pretty mare. Ooh, Sultry is nice too. So my pics are: