Yup....the first thirty seconds will get you a job, or get you thrown in the garbage. It's a total drag but that seems to be that way it is these days. I'd go with the most polished recording, but I almost hate giving that advice, because it implies that the person on the other end may have no subtlety at all....... so I'll make another suggestion

PHONE the person they're to be sent to (reasonably early in the morning) Be friendly, articulate, and advise them that a recording is on the way. Wait a week, and phone them again. I can't tell you how many folks I've hired for my radio show, 'cuz they showed some real interest rather than JUST sending a package. You have to do SOMETHING to jump the queue.

Good luck

Rick