Get a generic Cardbus USB controller and an external 2.5" IDE to USB case would be the cheapest and simplest solution, I would think. Put the SSD in the external first, clone the internal, then exchange them. I don't think the Wallstreet can boot from USB, hence doing the clone before the transplant.

And USB is always a nice thing to add to a "bridge" machine

/eta/ Oh, I see it comes with Firewire and USB cards - nice You won't actually need drivers, they're built in to OS 8.6 and above. At worst you may have to download the relevant components from Apple.

By the way, I agree, that's a nice price for a G4 upgraded Wallstreet with all those extras.