Whilst there is no harm in doing lots of research up-front, you will learn such a lot about aircraft, what they can do and what you enjoy doing from learning how to fly that you would be best not to make any firm decisions until you have a decent amount of training under your belt.
While you are training you will meet lots of people, hear lots of opnions, and perhaps even get to know anout aircraft for sale / places to fly from which aren't generally publicised.