The listing for mine said 3.0 ROMs with 3.1 WorkBench, so, that's what I expect. But, we'll see.
As for the CPU... I vaguely recall reading that some later chips (68040 and 68060) aren't as compatible with classic Amiga software as the 68030 and earlier. So, I'll probably stick with the 68040 and the on-board CPU (didnt 4000s have eithe a 68020 or 68030 on board?). Good to know the difference though.