Backing up PS3 data to the new hard drive from the old hard drive?

[Unknown Entity]

I'm upgrading my PS3 from 40GB to 640GB. I have the new hard drive, and I know what I have to do to change the hard drive - it seems like a very simple task.

However. I don't have an external hard drive large enough to back up all of my data. So pretty much, I could sit here all day and just send all my saves to my 2GB memory stick. I don't want to do that.

I want to know if I would I encounter any problems if I bought an enclosure for the old hard drive, and restore my PS3 from that hard drive using the restore option? I have data on there which can't be copied (Dragon Age, Assassin's Creed II and Heavy Rain, which is a BUMMER) - obviously that won't go to the new hard drive, but would that stop anything else going/will I be prompted?

Finally, umm... do I need to ground myself? I know how to, just looking around my place, that seems kind of hard. I could use my old PC case, but how important is it for just swapping out the hard drive on the PS3? All the youtube and written guides I've seen don't mention it.