Had to download modpack-anyWii.zip from another computer, it repeatedly asked me for a password on my PC, I thought I had the wrong password or something, but on my wife's PC it worked first time. No idea why, guess it was related to my PC, but just thought I'd mention it as it might be worth a go for anyone else having trouble downloading the modpack.
Had to use the non-prefered offline method to downgrade to 4.1j as we couldn't get a network connection. I may have disabled the network earlier as a precautionary method to avoid upgrades, after accidentally upgrading to 4.3 earlier.
Trying to get one of the USB loaders to work now.
Massive thanks to mauifrog, you're a legend.