Additionally if you are planning on adding more speakers and a sub, deck
power is definitely not going to be enough. Most headunits cant even put
out more than 20-25 watts RMS per channel. I think it is time that you
saved a little money and invest in some amplifiers, you can still keep
your factory deck though. Wire through an LOC (Line Output Convertor) to
the amps and run power and speaker wires and your good to go. In my
opinion the price you would pay for the upgraded Ford factory system
would probably end up costing you are around the same amount of money.
Car audio is really cheap these days and using eBay (wisely) can save
you a lot of money. Good Luck