I have a DFX in my car now, it holds the power. You will need to learn to drive around the chatter, sometimes when I am lazy you can hear it from outside the car. Also, it is very close to being an On/off switch for the 03/04 cobra, something you’d have to get used to as well.
Spec 3+ or DFX will be a good choice. Make sure you do all the associated upgrades when you have the trans out.
I will be switching to a twin disk setup next.