Hi N.,
Wrap - The Moby for when baby is little (0-6 months). My daughter loved this carrier and I always felt like she was a part of me when she was in it. Once they hit 15+lbs, they get a bit heavy.
Sling - New Native, Hot Sling or Maya for in and out of the car and quick trips. My favorite now that my daughter sits on my hip is the Over the Shoulder Baby Holder. This would have worked from birth (I just got it a few months ago). It is adjustable and has padded edges (this is key). I would not get one that is not adjustable since you are petite you want it to fit you perfectly and can also be worn by someone else - husband, mom, sitter, etc.
Carrier - I just purchased the Beco for a trip and we love it. My baby weighs 20lbs and we needed something else for longer periods of walking with her. The Beco is perfect and works front or back and also as a hip carrier when folded up. I have read that the Beco is better for petite women (but will still work with larger husbands). Would highly recommend and is way more comfy than the Bjorn.
Bottom line is I ended up with about 6 carriers! They all served their own purpose.
Best of luck!
D.