This might be an epic.

We need to dust off the previous work for PCI saq a-ep.
What work is remaining?
What does maintenance cost look like when live?

Business Reasons:
We should have much more control over payments forms with this new level of PCI. One example: This would allow a bunch of best in class techniques on the mobile form.
If we don't have this and choose to implement apple or android, we have to use some really hacky techniques to get the buttons to appear.
This would give us a greater range of options with current payment processors. This would decrease the need for new processors.