I've specifically asked Paul Pratt to implement the Classic since it also has a 68000 processor and contained within its ROM is a bootable version of system 6. Unfortunately, despite its similarity to the SE ROM, it would not work with the current builds.
His next focus is the Mac II and the 68020 processor, including NuBus. The 68030 is sometime off.
In addition to the Portable, the original PowerBook 100 also uses a 68000 processor and use the same 256K ROM type as the SE. Like everything else with Mini vMac, you'd need the somewhat rare ROMs from those machines.