Mini-assembler was in all II, II+ and //e. II had Integer Basic, II+ and //e had Applesoft. Can't remember which ones had SWEET16 though. May also be "all of them".
If all you want is LISP, burn it into an EPROM and replace the stock one.
It was absent from the II+ due to the larger Applesoft BASIC interpreter. If you had a "Language Card" (a 16K expansion that brought the machine to 64K) you could load Integer BASIC on the card and use the assembler.
If all you want is LISP, burn it into an EPROM and replace the stock one.