The tools in the Win8x64withTools ISO come pre-installed in the OS, so I don't believe there is a way to extract them. Anyway, I recommend downloading the Visual Studio 11 Developer Preview since the VS11 in the Win8x64withTools ISO only has the express edition. Warning, it's a 8.7GB install.
If the bandwidth is really a problem, you're stuck with the ISO:
If your problem is the size of the installer ISO then you may be able to get around that using the Windows AIK (Automated Installation Kit) to create a VHD Win8 image. I have not done that with Windows 8 so I don't know if it works. I recommend against running in a virtual machine because depending on your machine and the VM software it can get really sluggish. Windows 8 uses a lot of hardware acceleration and that doesn't always happen in a VM. I am running Windows 8 native off a VHD and that does work with just minor HDD read/write slowdown.
You can 'burn' the Win8x64withTools ISO to a USB flash drive using the Windows 7 USB/DVD Download Tool and that works great. One great walk through for using the USB tool with a VHD is by Scott Hanselman.
Hope that helps.
Update: While the separate download of VS11 doesn't appear to be the express edition like in the Win8 ISO, I'm not sure that is is the full edition.