Esses são os que eu tenho. Basta trocar lenny por etch.
# Repositorio de patchs de segurança
deb Debian -- Security Information lenny/updates main contrib non-free

# Repositorios regulares
deb ftp://ftp.br.debian.org/debian/ lenny main contrib non-free
deb Debian Multimedia Packages::Home lenny main
deb ftp.osuosl.org :: Oregon State University Open Source Lab testing main contrib non-free
deb Index of /debian testing main contrib non-free
deb ftp://debian.das.ufsc.br/pub/debian/ lenny main contrib non-free
deb Index of /debian lenny main contrib non-free
deb Index of /linux/debian lenny main contrib non-free
deb Index of /debian lenny main contrib non-free
deb ftp://mirrors.kernel.org/debian/ lenny main contrib non-free

# Repositorios CELEPAR
deb Index of /celepar lenny main non-free contrib
deb Index of /debian lenny main non-free contrib
deb Index of /security lenny/updates main non-free contrib
deb Index of /marillat lenny main

# Enlightenment DR17
#deb Index of /debian sid main contrib non-free

# Repositorios problematicos
#deb ftp://debian.las.ic.unicamp.br/debian/ lenny main contrib non-free
#deb ftp://ftp.pucpr.br/debian/ lenny main contrib non-free
#deb ftp://linorg.usp.br/debian/ lenny main contrib
#deb http://linux.iq.usp.br/linux/debian/ lenny main contrib non-free