Yes, you can set up as many investment plans as you like, for as many equities as you like.
However, you can't have more than A$20,000 in total unsettled buy orders at any one time.
Example: Let's say you want to set up four weekly investment plans of A$10,000 each, all of which are set to process every Wednesday. Our system would trigger the first two scheduled buy orders. However, you'd then reach our limit of A$20,000 in total unsettled buy orders, and your next two scheduled buy orders wouldn't trigger and would be skipped.