My buddy's Ruckus is pretty heavily-modified and it still feels slower than frozen molasses to me. You're lighter than I am but I think you will still be disappointed in its performance. His has aftermarket exhaust (full header-back), aftermarket carb, modified drive system (clutch/variator/etc) and a ton of other stuff. Basically he's spent almost $2000 in mods on the stupid thing and it still won't go over 45mph with him on it (he weighs 140lbs).
I'd rather have a small CB, like a 175 or a 305, etc.