Maybe you're trying to do too much too soon. If you're not even sure about going with O-gauge, build a smaller project first which can serve as a module unit for future expansion.
It's easy to get the impression from hobby magazines and forums that you have to have a big layout to have a good layout. Don't get sucked into that train of thought.
Trying to do too much can lead to burnout because it's a long ways to see light at the end of the tunnel. Just my two cents worth.
