Thanks @ OverFlow and Helmi for your detailed replies. Sorry this is getting pulled way OT. Look like it's turning into a newbies guide for using DriverPacks
I have loads other questions, but I think it'd be best to start a fresh topic for those.
I've read the Base Tutorial, (which seems to be pretty straight forward) nLite docs, and now reading RyanVM manual:
http://integrator.professorcpu.net/index.php?manual
Once I've got a general overview of the process I will first try to build an XP recovery disk with SP2 and hotfixes applied to it. I know this will work for a particular laptop, as this is the machine the original recovery DVD came with. So getting that far will confirm I know how to use nLite, and how to sliptream SP's and hot fixes, and create an ISO image and build a bootable recovery disk.
Once I have sorted that out, then all I need to do is create another recovery DVD disk using SP3 and hotfixes, and use DriverPacks_Base to add the missing drivers for my target laptop.