my guess would be a bigger tank. i would think that this tank should do you just fine if its your fist tank. if you havnt bought it yet i would: get this insteed
20g long
20#'s LR
aquaclear 70 (mod it to hold cheato-oogle it to find the mod)
2" sand/agrogate bed
depending on what you want for corals a T5 HO light
and then go from there. i dont know how much the eclipse 12 is but i just built somthing similar to what i gave you the list for and it cost about $250.00 and it looks really nice. the cost will be really in the rock and if you can find it cheap like i did ($1.00 per pound-uncured)
just some thought though