hi all, is there a way to to put totals under PO's or SO in quantities?

What do you mean?

If you mean Qty Totals, it will depend on where you want to use this data. If it's only for viewing in the UI, or on Advanced PDFs, you can just create a Custom Field sourced from a Saved Search which sums up the total for you. Otherwise, it will probably need scripting.

@markderrick thanks, that's what I mean. But is there also a way to have it at the bottom of all the item lines?

No, only as a Custom Field