Best media for 12G Eclipse

I have a 12G Eclipse that I keep at my office (FOWLR). I am wondering what would be the best media that I can put in the tray/bio-wheel area. I assume that there are better options than the stock carbon filter & bio wheel. My nitrates are currently pretty high, so if there is a particularly good media to help control that, that would be great.

Suggestions?

The tank setup:

12G Eclipse (stock lighting/filter)
100W Stealth heater
10-15 lbs of live rock
2" live sand

Inhabitants:

Yellow/Pink dotty back
Clark's Clownfish
Pistol Shrimp
Oreastor Reticulatus Starfish (I think... haven't been able to positively ID)

2 Turbo snails
2 cerith snails
3 nassarius
8 hermits

Thanks,
-AJ

 

Run carbon on there. BioWheels can often cause nitrate problems. They are little nitrate factories.