i used to have and shoot regular 8mm ( i had a bolex h8 ) and i also had a bolex h16. there is still a large community of regular 8mm film users out there. another name to keep in your hat for regular + super 8mm as well as 16mm is http://www.prepfilm.com/ . he sells film and can also have it processed.
i used to drop all my 8mm off at wal-mart / sam's club ... it was always picked up by fuji and forwarded to dwayne's and it was dirt cheep to have it processed. i think it cost me $4 no matter if it was a big roll ( 25 ' or 50' ).