Requesting advice regarding creating a custom Debian distribution

[icelinux@icelinux.net]

Hi,
  I have recently started a project to create a custom Debian
distribution DebIce which provides a desktop with very low hardware
requirements. I would appreciate any advice you could give me
regarding the following:

1) Inclusion of software not currently available in the Debian package tree.
  I have discovered there is some software not present in Debian which
is needed for my distribution. Some of this software is already
packaged for Debian by others and some of it is not.
2) Creating and maintaining a separate package repository to use for
installation.
  I want to use the Debian packages whenever possible, however there
will be some packages that will require configuration file changes.
Also, as previously mentioned, some software is not available through
the Debian package system. I currently think it would be best to use 2
repositories for installation - my repository and the Debian
repositories - to fulfill this purpose in order to avoid having to
resign all of the packages and to make certain updates were available
as soon as possible.
3) Any issue and problems you think I may encounter.