Evan,
How much do you want to spend? There were many inexpensive MTB stems in the late 80's and early 90's which will meet your needs (check some of your LBS's) although the angle may be less than ideal, but if you want classy, that will up the ante. Bob Jackson made (still makes??) a wonderful stem with a built in adjuster, but these have gone for over $150.00 on eBay. Check with some of our English List members, they may be able to help you out.
Chuck Brooks
Malta (52o today!!) NY