Since you are just installing, you get to download all the patches since launch. Bad news is, you get to install ALL the patches.
Folks that have been playing have had many more but smaller downloads. Unfortunately, the patches don't come on disk and are only available via download.
You can select to turn off some of the added content to download, specifically the voice add-ons that were made available a few months ago. On your login screen, select (I think) download options, and deselect (I think) extra content. That should cut off some of the extra optional voice-over downloads and may trim a bit of fat.
If you can, get cable. I understand it may not be so easy for you, but believe me, it is well worth it.