Haven't been back to this thread for awhile, but please be sure to take care of any issues in the basement - paint (walls and floor), moisture (as Mark observed), electrical, and any other projects - before you start building. As you design, be sure to allow for access to any pipes, wiring, ductwork, etc. that will be above the layout. Depending on where you are relative to the stairs and mechanical items, be sure there's room to maneuver a new washer, water heater, or furnace into place. These are all easy to overlook in the push to build a layout.
I like your idea regarding modular benchwork. First layout in your first house - you'll almost certainly need to make adjustments down the road.
In addition to the many good layout threads that are mentioned above, a couple of YouTube channels by forum members who are working in similar spaces are: https://www.youtube.com/user/JDStucks and https://www.youtube.com/c/RBPTrains.
Keep up the good work.
