Here is my repos list you can have one created at the following address.
http://www.ubuntulinux.nl/source-o-matic
If you use my repos list you will need to import some keys with the following commands.
gpg --keyserver subkeys.pgp.net --recv KEY
gpg --export --armor KEY | sudo apt-key add -
As for the proxy settings. You will need to configure those. Never really had to deal with a proxy server regarding apt-get.
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# Automatically generated sources.list
#
http://www.ubuntulinux.nl/source-o-matic
#
# If you get errors about missing keys, lookup the key in this file
# and run these commands (replace KEY with the key number)
#
# gpg --keyserver subkeys.pgp.net --recv KEY
# gpg --export --armor KEY | sudo apt-key add -
# Ubuntu supported packages (packages, GPG key: 437D05B5)
deb
http://us.archive.ubuntu.com/ubuntu dapper main restricted
deb
http://us.archive.ubuntu.com/ubuntu dapper-updates main restricted
deb
http://security.ubuntu.com/ubuntu dapper-security main restricted
# Ubuntu supported packages (sources, GPG key: 437D05B5)
deb-src
http://us.archive.ubuntu.com/ubuntu dapper main restricted
deb-src
http://us.archive.ubuntu.com/ubuntu dapper-updates main restricted
deb-src
http://security.ubuntu.com/ubuntu dapper-security main restricted
# Ubuntu community supported packages (packages, GPG key: 437D05B5)
deb
http://us.archive.ubuntu.com/ubuntu dapper universe multiverse
deb
http://us.archive.ubuntu.com/ubuntu dapper-updates universe multiverse
deb
http://security.ubuntu.com/ubuntu dapper-security universe multiverse
# Ubuntu community supported packages (sources, GPG key: 437D05B5)
deb-src
http://us.archive.ubuntu.com/ubuntu dapper universe multiverse
deb-src
http://us.archive.ubuntu.com/ubuntu dapper-updates universe multiverse
deb-src
http://security.ubuntu.com/ubuntu dapper-security universe multiverse
deb
http://archive.ubuntu.com/ubuntu dapper-backports main restricted universe multiverse
#created by arniedappersecond
deb
http://theli.free.fr/packages/dapper/ ./
# Seveas' packages (packages, GPG key: 1135D466)
deb
http://mirror2.ubuntulinux.nl dapper-seveas all
# Seveas' packages (sources, GPG key: 1135D466)
deb-src
http://seveas.theplayboymansion.net/seveas dapper-seveas all
# Cipherfunk multimedia packages (packages, GPG key: 33BAC1B3)
deb
ftp://cipherfunk.org/pub/packages/ubuntu/ dapper main
# Cipherfunk multimedia packages (sources, GPG key: 33BAC1B3)
deb-src
ftp://cipherfunk.org/pub/packages/ubuntu dapper main
# Bleeding edge wine packages (packages)
deb
http://wine.budgetdedicated.com/apt dapper main
# Bleeding edge wine packages (sources)
deb-src
http://wine.budgetdedicated.com/apt dapper main
# The Opera browser (packages)
deb
http://deb.opera.com/opera etch non-free