Personally, I would not buy a bike on-line if I had not actually ridden it.
As a seasoned cyclist, one thing I have learned is the most important thing about a bike is that you will use it. In the long run, it really matters SO LITTLE whether it's $200 or $800.
I would visit a number of shops, tell them what you are looking for, then test ride the appropriate bikes. If there's a model you are interested in and they don't have one you can test, call around and find someone who does. It sounds like you wanna have this done "1,2, 3!", but you really should take your time.