The easiest way is a clock port adapter that fits under the 68000, then you can get a single parallel port card (IOBlix did one)
There are also lots of A2000 options, The best imho is the Z2 IOBlix which has 2 parallel and four serial ports. There are others less ports though.
As for specific cards for the A500 & A1000 side expansion slots, no Im not aware of one.
Just out of interest, why do you need an extra parallel ports?
