[Clivey]

Just choose the higher specced version of the Mac Mini if you want more memory and HDD...Another option is to upgrade RAM yourself, if anything were to go wrong and the warranty thing is true, just remove the memory you installed and replace it witht he original before ssending it back for any warranty repairs etc. External HDDs are as cheap as chips now so if you did eventually need more space that'd be easier and maybe cheaper than replacing the one inside the Mini.

But if you were after a better specified Mac, you're better off with an iBook...it might seem more expensive but it comes with a screen and speakers (obviously as they're built in) as well as a keyboard and mouse...plus they're generally better machines.