From what he's saying, it's only 45 seconds until the icons are visible - that doesn't sound like anything's holding up the startup sequence all that much, especially if the machine's loaded with graphics cards, network cards, lots of drives etc. If it's just the background image that's taking that long, I'd put money on it being a JPG image, and possible even set in the preferences to "Scale well", which is very, very slow on anything other than a simple IFF. Load the background pic into ImageFX, TVPaint or something and save it as an IFF with a similar resolution to the Workbench screen, and set the prefs to "Centred" instead and it'll cut 2 minutes off that time.
Edit: Just read the advert now - if the background picture has more colours than the Workbench has free pens then that'll add to the delay as well. And whatever about an 060, an 030 is going to take an age to scale any image.