Correct, there never was a 68K VPC. SoftWindows/SoftPC are your primary options here.

Since we're talking VPC, though, IMHO the only ones worth getting are 3 and 6 -- 3 because it had the best graphics performance vs. compatibility (I played Shogo on Windows 98 with software rendering on this MDD), and 6 because it has the widest compatibility -- you can throw a Knoppix Live CD at it and use Firefox 3 "on OS 9." Before I started working on Classilla, that was in fact exactly what I used.