Not too much, A rough idea of what you would need: The prices are ballparks
Wiring harness - $80ish
Motonic DME - $60-80
Air flow meter - $30-50
I think the PO had the car's ignition system changed to wasted spark with MS so you'll also need stock wires, cap+rotor and ignition coil. price may vary if you decide to get everything new or used or the parts new and used
The kinda big thing is the chip, from what i remember your motor is a 2.7i "stroker" so the stock chip may not work too well. I think MarkD has an off-the-shelf chip for your mods, you should contact him and see!
Again doing these things are a lot cheaper than doing a swap!