I don't know about soft modding, but I have a hard modded XBox with an 80GB hard drive and the AutoInstaller Deluxe CD iso:
http://www.google.co.uk/search?hl=en...deluxe&spell=1
It basically prepares the new harddrive, installs XBox media centre, emulators, games and films to hard drive tools etc - it's brilliant!
The XBox came alive that day for me. It felt like a new machine!