Quicktime and other system software are already installed, but the
updates have to be downloaded. I don't know if ou have uploads set to automatically download, which you may want to disable on a dial-up connection (go to System Preferences> Quicktime and System preferences> Sotware Update).
Since beyond Quicktime you presumablly want the
Combo 10.4.6 Updater for PPC, maybe the latest iTunes, the Jave engine update, et al., it may be quicker to instead try this:
--- use Software Update and note what programs it's suggesting
--- look up the address of the nearest Apple Store (the Apple Store website shows two in London, Brent Street and Regent Street)
--- take a blank CD-R or two to the Store's Genius Bar
--- do to the Apple Downloads website and download the software installers and updaters onto the CD-R
--- burn the CD-R, thank the staff, and take the discs home
(At 4.5 hours just to download Quicktime, that should save you a fair bit of time.)