@kickycan,
The world is crying out for an acoustic folk duo specialising in Sepultura covers.
Perhaps before we brainstorm, we should review what has gone before (so we don't double up):
While
Hayseed Dixie is a great idea (country versions of AC/DC songs) and
Big Daddy was pretty funny (proto rock n roll combo is captured in the Korean War and released 30 years later and do mid fifties versions of mid 80s songs) my favourite is still
Dread Zepellin (Elvis Presley didn't die, he joined a reggae band that only plays Led Zepellin covers).