I would look at the AI Primes. As you see above, people are using them, and for a smaller 10g sump or section it would probably be perfect. You could probably keep higher light corals (SPS) directly underneath, and have lower light LPS or softies towards the sides.
I imagine running it at 100% you'd probably see just fine growth, if it wasn't too much light.
Usually, on a nano, any upgraded light will get impressive growth if all other tank parameters can be maintained. When people around here make the jump from stock lights to aftermarket lights, it almost always is enough to carry them through the rest of the hobby. Most people don't make it that far, or get good growth, because keeping parameters stable in a nano is very difficult. If you have it plumbed into your main tank though, and have that tank running nicely, then you shouldn't have that problem at all.