Mine is a 6 port. It's really hard to justify the extra cost of the 6 port looking back. There's the cost of the motor and the bigger hassle is the engine control. When you add in the complexity of controlling the 6 port actuators and 6 vs 4 injectors it bumps you up from a base model stand alone into much more expensive ECU's. On either motor I found that a late 90's mustang 4.6 throttle body bolts right up. That gets you by the drive by wire throttle that comes on the engine. They only run ~$30 brand new on ebay.
Here's a run down of outputs you need to control on the two motors. this doesn't include fuel pump, fan or idle control which is another 3 outputs.
6 port needs 10 or 11 ecu outputs depending on year of engine
Injectors- 2 or 3 depending on year
04-08 engine uses 6 injectors that can be batched into 3 pairs of 2
09-11 engine uses 4 injectors that can be batched into 2 pairs of 2
1 output, 3&4 port actuator
2 outputs, 5&6 port actuator
1 output, variable intake valve
4 outputs, ignition coils(these can't be run wasted spark)
4 port needs 8 outputs
2 outputs, fuel injectors- 4 injectors batched into pairs of 2
1 output, 3&4 port actuator
1 output, variable intake valve
4 outputs, ignition coils(these can't be run wasted spark)
If you skip the idle control (I did and it's been a non-issue) most bare bones ECU's will do the 10 outputs total you need for a 4 port motor. I really like this guy for a 4 port motor-
https://www.fueltech.net/products/ft450-efi-systemyou even get a configurable dash in the deal.