Reinstalling Leopard on an upgraded HDD on Macbook

Whenever Snow Leopard is delivered, I want to go ahead and start fresh with a clean installation of 10.5 on my wife's MacBook. Also, I have a new HDD that I want to put in at the same time. So, my game plan is: back up all of my wife's files to a USB drive, put the new HDD in the Macbook, install Leopard from the original CD-ROM, then upgrade to Snow Leopard, then reinstall apps and drop all of my wife's files back in.
The only part that bothers me is whether I'll have any trouble installing 10.5 on the new upgraded HDD. I know that with XP, re-installing on an old system with upgraded hardware can be a risky proposition, because drastic hardware changes can cause activation to fail.
Does anyone see any problem with my plan? Thanks.

You will have no activation/licensing issues since OSX does not have this sort of requirement.

The only time you would see any issue like this is if you attempt to use Leopard disks that came with one machine on a different computer. This doesn't apply in your case so your all set.