Since you are already comfortable buiding with aluminum, and you want enclosed, high-visibility flight at low speeds, the Kolb MK III would be an excellent choice.

This aircraft is easy and quick to build, operates from *very short* fields (300 ft or less) and is a baby carriage to handle on the ground and in the air. Engine choices can be 2 or 4 stroke in the 50-75 hp range as needed for your altitude.

This is a long-proven successful design that you will come to love and respect as the hrs build up.