Welcome to CHR! Hope you enjoy a long stay, and get a build thread started on the 'burban.

If I Google "1965 Chevy Suburban Quarter Panels" there are several places that pop up besides LMC and Classic Industries, like Rock Auto and NorAmStore ( link - https://www.google.com/webhp?sourcei...uarter%20panel ), but you did say "...and other web sites" so you may have already checked them out. Like Ryan said, you're likely looking at patch panels vs full quarters for a '65.

Good luck in the search!