Sheila, since I'm constantly mixing and matching stems and handlebars, I keep a variety of stem spacers on hand. I do prefer a taller handlebar height setup with more spacers under the stem, typically 4 or 5. Remember, though, you can place the stem between spacers, with spacers on top of the stem, if you want to go lower. No law that says the stem has to always be in the topmost position. Bottom line is not to cut the steerer tube height to short/low. Once you cut it, you're stuck with that height. Totally a personal preference, though, so see what works for you.

On my new Log Lady build, I'm going carbon on the handlebar and it will be a conventional MTB bar. Frightfully expensive, but I have a carbon handlebar on my Gunnar that the former owner had used for his build and I love the carbon. Makes for very responsive handling and, best of all, carbon will absorb some of the road/trail chatter. Also going carbon on the seat post on the new LL for same reasons. This new LL is my first ever custom build, so I want to take my time and do it right. Never would have considered carbon if I hadn't' gotten carbon on the Gunnar.