GOG.com offers some of the old lucas arts games, like monkey island. but they only have the windows versions.
but since they packed the installer with inno setup, you can just extract the content using innoextract, and run the game with scummvm. no need to use wine!
innoextract --output-dir <output_dir> <path/to/installer.exe>
then start scummvm, add new game, choose your output folder and start playing. :)