Babyruth,
The biggest difference between latin and standard skirts is length. In my experence, it's easier to wear a latin skirt for standard than it is to wear a standard skirt for latin. Standard skirts have too much material whipping around which makes it a little more difficult to "see" some of the leg and hip actions. But a really top-notch pro or coach won't be fooled.
Me - I just wear a pair of jazz pants and a top for both standard and latin lessons and practice - let 'em see it all as clearly as possible.
Good luck.