I did the same some time ago. I used a full 3d version (untextured) for the collisions and a highres version of my board for graphics only. Don't use the physic engine for such a simple game. There are a lot of problems occuring with this build in physicengine. For example: It is very difficult to prevent your sphere to bounce into the z Direction out of your board if you are using alot of round shapes. Ok, you can correct the position, but the physical movement is not accurat annymore.
Use simple c_move code with polycollision. It is efficient enough for a breakout clone.
One thing, if your player platform is moving toward the ball and the sphere/ball is moving towards the player you have to correct the position, because it often happens, that the ball ends up in the player.
I hope that helps.
MfG
Patrick