What Fish would you add?

As my 10 gallon build thread says I plan on upgrading to a 40 gallon. I am selling my Ball python and Traxxas Tmax 3.3 RC Truck, so if your interested let me know. I thought my build was going to take longer, but I decided to sell these items to speed up the build.
The only item I know for sure I am getting is the MU 135 Watt Led fixture.
OK now here comes the questions!!

45 gallon or 40 gallon? Which will be better for the light fixture I am planning on getting?
What would be a good stocking list? I am looking for really active fish.

 

The fixture is good for a 24 x24 area.

Chromis are very active fish. A sixline wrasse is also very active.

 

Ok thanks! I was thinking around 5-7 fish, depending on size and bio load. Would 3 chromis make a school? That would be really cool. I am a huge fan of wrasses.

Any other ideas guys?

 

I would go with 5 to 7 of Chromis they just seem to be better that way.

 

O ok. I just don't want a school of chromis though. I was thinking going the wrasse route. I think they are prettier.

 

I would do 3 cromis, a wrasse and a firefish