Originally Posted by oldbobcat

First, the bottom bracket has nothing to do with the stem. Forget about that.

Regarding reach, there are two components after frame reach--that's stem length and handlebar reach. The right combination of this is one that gives you an 80-90 degree angle from the back to the upper arm when the hands are on the lever hoods and the elbows are slightly bent, down, not out. Next, measure your stem length and handlebar reach. Handlebar reach is the distance from the centerline of the top of the bar to the centerline of the farthest reach of the drop. Add the two, subtract the distance you want to reduce, and look for a combination that gives you that reduction.

Regarding bar reach, I consider 80mm to be about medium, so anything under 80 is short. Even when using a long stem, I prefer shortish bars. My hands can move around on them more easily. Ritchey has several compact bend bars with 73 mm reach that I recommend. Their WCS stems are also stiff and light.

Regarding handlebar height, level with or a couple centimeters lower than the saddle is a starting point for most beginners. Higher, and you can't get the pull from you shoulders, and lower can be a stretch for someone starting out. It's hard to give hard advice without seeing you on the bike, but I hope I've given you ideas on how to figure this out for yourself. Listen to your body.