"In other words, I should get ShapeShifter to run Diablo..."
Sorry, but Diablo1&2 and Starcraft require a powermac :-(
You would need a CyberstormPPC with iFusion to make these games run. Diablo1 and Starcraft will probably run fine, but I doubt that you can make Diablo2 run smoothly, it needs quite a lot resources... you would need a g-rex or a Permedia2 to allow it to have enough bandwitch (a mediator or a prometheus don't have as much bandwitch). And even with enough bandwitch you would need the maximum of memory available free, a scsi hard drive (afaik it isn't supported directly by iFusion so you would need a hardfile with lots of buffers), a soundcard (well, in peecee switching off the music helps to speed up the game)... well... I doubt that you'll be able to make it run smoothly even with the minimum resolution of 640x480 and 16bits.
But Diablo1 is a different story and should run well in the CyberstormPPC. Starcraft requires a little more cpu power but it will probably run more or less smoothly. Both games run at 640x480 and 256colours so even a graphic card with a slow Z3 bus like the CV3D may be enough.