You should just get the 4 in my opinion. It would be very helpful, and anyways, you wouldn't have to use all 4 paddles.
I have a Scuf with 2 paddles, and it is great and comfortable. I'm not too sure how good it would feel to hold the controller with all 4 paddles in the back.
So I say just go with 4 if you want.
On my 360 before my cat broke my scuf lol I had 4 paddles and absolutely loved it but after it broke I was completely disabled like I'm a comp player and I have to jump shot and shit but I was so used to playing with paddles I couldn't play regularly LMAO.. But anyway I learned how to play claw and now I feel like I wasted so much money on the scuf because claw is so much easier, better and cheaper IMO..