Just wondering. How much are you going to pay for this car?
Have you ever done a head job on a modular motor before?
Instead why don't you consider getting the motor from a Mark 8 or Lincoln Aviator and use the whole motor. Seems like a better use of the $$. I suspect that the any difference saved by going Continental will be eaten up by the cost of the cylinder head changing kit and the new timing parts needed.
This hasn't even started with finding a DOHC front timing cover, intake manifold, and exhaust manifold.
Do you have a budget? Will you be doing the work yourself?