Tartan Giant,
WinXP Home and WinXP Pro are the same OS, just that Pro has extra programs built in. If you do not want to do a fresh install, you can just keep WinXP Home that computer and use a network to transfer your data over or you could burn your data to a CD and then load them in to the new computer.
If you clone the drive, you will have both computers with the same name and user information, if you plan on having both on a network, you will have some additional changes needed, since both computers will have the same settings on a network.
Take Care,
Richard
P.S. I do prefer Pro to Home, since Pro has more programs, which means you need less third party programs vs Home.