I went to 2 LBS' (when I lived in Corpus) and even went to Houston(hometown) to search their bike shops. I tried about 8-10 different bikes, women specific & men's specific. Like you, I wanted a starter bike, but at the time knew I would probably/possible want to upgrade in the future. I ended up with the men's Giant OCR 3.....it was just the most comfortable for me, in my price range. I've only changed out the pedals & seat, but the way my body is shaped, it fits me to a tee

As for my mountain bike....it seems to be a slightly different process. I'm now in Aggieland & when I explained what I wanted, the guy told me he didn't have anything in my size, but did my measurements & currently has 3 bikes on order for me to try out. I've already put down a deposit, so I will go with him(he offers lifetime maintenance) and when those 3 arrive, I'll go from there.

Anyway, good luck, but definitely shop around!