Does anybody know of a mod that allows your PC to wear Carths Flight Suit in K2?
Do you mean Carth's Default Clothing? 'Cause you could do some minor appearance.2da editing to make your character's Default clothing into Carth's.
But if you meant port it from Kotor I, then you legally can't. At least, you can, but you can not distribute it.
Well, actually you can't. As the model included in TSL (Which I believe there is) has Carth's head attached to it. And that is a problem when you want to use it on your own personal PC. ;)