Philip, as far as packaging programs goes for Linux it really depends on the distribution or distributions you intend to target. There really isn't a one size fits all solution in terms of package manager. Although, it is possible to install and use other package managers on a distribution other than the one it was designed for.
As you may know there are many brands of Linux called distributions. Usually there is a major distribution and then there are derivatives that use the same package manager and things like that, but perhaps come with different software, default desktop, etc. There is the Debian distributions such as Debian, Ubuntu, Vinux, Sonar, etc which use the DPKG package manager. The Red Hat distributions such as Red Hat, Fedora, Mandriva, Cent OS, and so on all use a package manager called RPM. Arch Linux uses a package manager called Packman. So it really depends on what Linux distribution or distributions you intend to support here.
That said, the majority of the blind Linux users I know usually use Debian based derivatives such as Debian, Ubuntu, Vinux, Sonar, Trisquel, and so on. In terms of numbers you'd definitely want a DPKG package as that would get most of the blind Linux market, but certainly not all. I know a few Fedora users out there and know of a few people who use Arch. So you can either build extra packages for those systems, or you might use an application like Alien to try and convert your setup packages from one format to the other.
Of course, there is nothing saying you have to use a specific package manager. You could simply write a simple shell script that copies files into the proper directories, sets environment variables, and your done. No hassle figuring out what package manager this or that Linux distribution uses.
In fact, this is what most commercial software developers end up doing. Cepstral, for example, simply uses a shell script to install their commercial voices to /opt/cepstral, sets up environment variables, and they don't mess with DPKG, RPM, Packman, etc because there are just too many different package formats to possibly support them all. I often do this myself when I write Linux applications as I usually don't know which type of distribution my end users will be running.
Sincerely,
Thomas Ward
USA Games Interactive
http://www.usagamesinteractive.com