If you think you will need a stem shorter than 9 cm I recommend selling the frame and buying the next size down. If you use a 70 or 80 you really affect the handling. Ideally you should be using a 10-12 cm stem. On a 54 cm bike i typically use a 110, on a 55 I use a 100 and i typically won't buy a 56. I had a wonderful Lemond Buenos Aires in a 55cm but the damn thing fit like a 57 so i had to sell it.

If you're looking at early 90's parts I'm assuming you will be buying a quill stem? If you want your handlebars level with your saddle, you might consider the Nitto Technomic Deluxe. Just remember that with quill stems, the higher the bars go the shorter the reach.