I worked in broadcast TV back in the 80's. I still see countdowns on reels from ad agencies but to tell you the truth, I don't know why. The purpose of the countdowns was to be able to play back the spots live, on cue. Don't know as though anyone does that anymore. Most cable systems and broadcasters build spot reels or dump them onto servers for digital playback. However, if you feel the need to do this and you have the software, you could create/animate one yourself or if you know someone with Premiere, they could generate one and pass it off to you. I deliver spots to cable with only bars, tone, and slate.
Go to my website and click on the FREE STUFF Link. There you'll find a countdown clock that you can use. It's a PAL CODEC but just change it in FCP or whatever edit system your using.