I went with aluminium vs carbon a couple years ago. Ehen i was young and strong I twisted steel frames over time so I just don't trust carbon at my weight.
I am not very knowledgeable with bike types but my suggestion is for you to visit a big bike shop where you can choose from an array of models and types. It is also my policy to try out the bike to get the feel of the riding. It's not only the looks that would matter because in the long run, the comfort of riding will matter most. I had tried a bike that is unsteady despite my careful steering. There's also one that had a heavy pedal. When you try to bike, you get assurance that you get what you like.