This a personal preference to you ,as others have said .For me some boards work better with Quads others work better with thruster
I found that wider tailed boards work better with Quads ,or if you are looking for more speed and drive on a board ,Quads are the go .
I have a 9.1 acid ,I like it with thrusters ,it has a narrow tail .tried it with the quad ,it just made it go too fast and too straight ,
now its up to you to explore ...

and don't forget to try a twin with a small centre too .
Or with Quad s you can mix you fins up with different sizes too,
also different flex,I like with a quad ,flex fronts and stiffer rears .