"p.s. My client that owes pushing 30k is asking how long he has to pay that? My answer is how long do you want to pay interest/penalties but....... is there some sort of outer limit to get it done before the IRS takes collections to the next step?"

If the tax return has been submitted without a payment IRS will send a notice for payment with a due date.  If the client doesn't pay by the due date another letter will go out....etc etc    Your client will know based on those letters when IRS is ready to take collection action.