Do you need more bandwidth? Is the Arduino even capable of keeping up anyway?
That chip has a 1MHz unity gain bandwidth product.
That means, at a 1:1 gain (no amplification) it has 1MHz of bandwidth. The bandwidth falls (roughly) in proportion with the gain.
So, a 10x gain would give 100KHz of bandwidth.
15x gain would be around 66KHz of bandwidth. That's still plenty for a lowly Arduino to keep up with. Now, if I were using a dsPIC sampling at 1.1Msps, then yes, I'd be thinking about more bandwidth (and a low noise, high speed op-amp).
But for this application? I don't see the point.