Hi guys,
Desided to jump into your thread.
John,
Go for Bison/Buffalo with no any doubts, as Sylvi suggested. You'll get the most soft, well-breatheable, durable and comfly boots which will last indoor use for ages. Just make them snug enough, as snug so won't even feel comfortable with them for first 2-3 days of wearing. After that mocs will stretch and will be "just right" for your feet. Otherwise, if they "just right" right off your sewing table, they'll get very loose after day or two.