This is something I think about a lot
I try to choose drivers that aren't already hired by other factories.
So, here goes:
Morgan Aero 8 GTE-Pro
Car 1:
Dan Cammish
Fernando Rees
Bruno Senna
Car 2:
Ludovic Badey
Kuba Giermaziak
Katherine Legge
Car 3:
Nicolas Prost
Jerome d'Ambrosio
Robert Kubica
Some picks are a little random perhaps (Ludovic Badey), but none are less than quick, consistent, performers.
I could also do an alternate line-up that consists of almost exclusively Super GT drivers